Clients not reporting to WSUS Server

Hi 

I recently installed WSUS on windows server 2008 spy, i appear to be having a common issue where some client machines (around 10 out of 70) have a not yet reported status in the wsus console, i have tried the following troubleshooting:

1.) Checked GPO was applied correctly ->it was

2.) Checked registry settings and my wsus server appears in [HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate] 

3.)Typed a. Stop the Automatic Updates service 
b. Rename the software distribution folder (i.e. C:\Windows\SoftwareDistribution). 
c. Restart the Automatic Update service 
d. Run wuauclt /resetauthorization /detectnow 
e. Run wuauclt /reportnow

All appeared as they should so im a little stumped any help would be appreciated. 

Windows update log file attached

2013-06-1211:40:36:7479809ccAU###########  AU: Uninitializing Automatic Updates  ###########
2013-06-1211:40:41:1539809ccReportCWERReporter finishing event handling. (00000000)
2013-06-1211:40:41:2159809ccService*********
2013-06-1211:40:41:2159809ccService**  END  **  Service: Service exit [Exit code = 0x240001]
2013-06-1211:40:41:2159809ccService*************
2013-06-1211:42:09:81698012bcMisc===========  Logging initialized (build: 7.6.7600.256, tz: +0100)  ===========
2013-06-1211:42:09:81698012bcMisc = Process: C:\Windows\system32\svchost.exe
2013-06-1211:42:09:81698012bcMisc = Module: c:\windows\system32\wuaueng.dll
2013-06-1211:42:09:81698012bcService*************
2013-06-1211:42:09:81698012bcService** START **  Service: Service startup
2013-06-1211:42:09:81698012bcService*********
2013-06-1211:42:09:81698012bcAgent * WU client version 7.6.7600.256
2013-06-1211:42:09:81698012bcAgent * Base directory: C:\Windows\SoftwareDistribution
2013-06-1211:42:09:81698012bcAgent * Access type: No proxy
2013-06-1211:42:09:81698012bcAgent * Network state: Connected
2013-06-1211:42:54:85498012bcReportCWERReporter::Init succeeded
2013-06-1211:42:54:85498012bcAgent***********  Agent: Initializing Windows Update Agent  ***********
2013-06-1211:42:54:85498012bcAgent***********  Agent: Initializing global settings cache  ***********
2013-06-1211:42:54:85498012bcAgent * WSUS server: http://Servername
2013-06-1211:42:54:85498012bcAgent * WSUS status server: http://Servername
2013-06-1211:42:54:85498012bcAgent * Target group: (Unassigned Computers)
2013-06-1211:42:54:85498012bcAgent * Windows Update access disabled: No
2013-06-1211:42:54:85498012bcDnldMgrDownload manager restoring 0 downloads
2013-06-1211:42:54:85498012bcAU###########  AU: Initializing Automatic Updates  ###########
2013-06-1211:42:54:85498012bcAU # WSUS server: http://Servername
2013-06-1211:42:54:85498012bcAU # Detection frequency: 22
2013-06-1211:42:54:85498012bcAU # Approval type: Scheduled (Policy)
2013-06-1211:42:54:85498012bcAU # Scheduled install day/time: Wednesday at 14:00
2013-06-1211:42:54:85498012bcAU # Auto-install minor updates: Yes (User preference)
2013-06-1211:42:54:85498012bcAUSetting AU scheduled install time to 2013-06-12 13:00:00
2013-06-1211:42:55:08898012bcAgentCreated new random SusClientId b8ecf920-f600-4602-82fc-c64204893aa9. Old Id: none.
2013-06-1211:42:55:08898012bcReport***********  Report: Initializing static reporting data  ***********
2013-06-1211:42:55:08898012bcReport * OS Version = 6.1.7601.1.0.65792
2013-06-1211:42:55:08898012bcReport * OS Product Type = 0x00000030
2013-06-1211:42:55:10498012bcReport * Computer Brand = LENOVO
2013-06-1211:42:55:10498012bcReport * Computer Model = 8808EJG
2013-06-1211:42:55:12098012bcReport * Bios Revision = 2JKT47AUS
2013-06-1211:42:55:12098012bcReport * Bios Name = Ver 1.00PARTTBL,
2013-06-1211:42:55:12098012bcReport * Bios Release Date = 2008-08-04T00:00:00
2013-06-1211:42:55:12098012bcReport * Locale ID = 6153
2013-06-1211:42:55:12098012bcAUSuccessfully wrote event for AU health state:0
2013-06-1211:42:55:12098012bcAUInitializing featured updates
2013-06-1211:42:55:12098012bcAUFound 0 cached featured updates
2013-06-1211:42:55:12098012bcAUSuccessfully wrote event for AU health state:0
2013-06-1211:42:55:12098012bcAUSuccessfully wrote event for AU health state:0
2013-06-1211:42:55:12098012bcAUAU finished delayed initialization
2013-06-1211:42:55:1359801444PTWARNING: Cached cookie has expired or new PID is available
2013-06-1211:42:55:1359801444PTInitializing simple targeting cookie, clientId = b8ecf920-f600-4602-82fc-c64204893aa9, target group = , DNS name = machine name
2013-06-1211:42:55:1359801444PT Server URL = http://Servername/SimpleAuthWebService/SimpleAuth.asmx
2013-06-1211:42:55:229980dfcAUTriggering AU detection through DetectNow API
2013-06-1211:42:55:229980dfcAUTriggering Online detection (non-interactive)
2013-06-1211:42:55:22998012bcAU#############
2013-06-1211:42:55:22998012bcAU## START ##  AU: Search for updates
2013-06-1211:42:55:22998012bcAU#########
2013-06-1211:42:55:22998012bcAU<<## SUBMITTED ## AU: Search for updates [CallId = {C2E5A5C3-EFAC-4889-889E-0BDFC048EAA3}]
2013-06-1211:42:58:2299801444PTWARNING: GetCookie_WithRecovery failed : 0x8024000b
2013-06-1211:42:58:2299801444PTWARNING: RefreshCookie failed: 0x8024000b
2013-06-1211:42:58:2299801444PTWARNING: RefreshPTState failed: 0x8024000b
2013-06-1211:42:58:2299801444PTWARNING: PTError: 0x8024000b
2013-06-1211:42:58:2299801444ReportWARNING: Reporter failed to upload events with hr = 8024000b.
2013-06-1211:42:58:2299801444Agent*************
2013-06-1211:42:58:2299801444Agent** START **  Agent: Finding updates [CallerId = AutomaticUpdates]
2013-06-1211:42:58:2299801444Agent*********
2013-06-1211:42:58:2299801444Agent * Online = Yes; Ignore download priority = No
2013-06-1211:42:58:2299801444Agent * Criteria = "IsInstalled=0 and DeploymentAction='Installation' or IsPresent=1 and DeploymentAction='Uninstallation' or IsInstalled=1 and DeploymentAction='Installation' and RebootRequired=1 or IsInstalled=0 and DeploymentAction='Uninstallation' and RebootRequired=1"
2013-06-1211:42:58:2299801444Agent * ServiceID = {3DA21691-E39D-4DA6-8A4B-B43877BCB1B7} Managed
2013-06-1211:42:58:2299801444Agent * Search Scope = {Machine}
2013-06-1211:42:58:2299801444SetupChecking for agent SelfUpdate
2013-06-1211:42:58:2299801444SetupClient version: Core: 7.6.7600.256  Aux: 7.6.7600.256
2013-06-1211:42:58:2609801444MiscValidating signature for C:\Windows\SoftwareDistribution\SelfUpdate\wuident.cab:
2013-06-1211:42:58:2759801444MiscMicrosoft signed: Yes
2013-06-1211:42:58:2919801444MiscWARNING: Digital Signatures on file C:\Windows\SoftwareDistribution\SelfUpdate\wuident.cab are not trusted: Error 0x800b0001
2013-06-1211:42:58:2919801444SetupWARNING: SelfUpdate check failed to download package information, error = 0x800B0001
2013-06-1211:42:58:2919801444SetupFATAL: SelfUpdate check failed, err = 0x800B0001
2013-06-1211:42:58:2919801444Agent * WARNING: Skipping scan, self-update check returned 0x800B0001
2013-06-1211:42:58:2919801444Agent * WARNING: Exit code = 0x800B0001
2013-06-1211:42:58:2919801444Agent*********
2013-06-1211:42:58:2919801444Agent**  END  **  Agent: Finding updates [CallerId = AutomaticUpdates]
2013-06-1211:42:58:2919801444Agent*************
2013-06-1211:42:58:2919801444AgentWARNING: WU client failed Searching for update with error 0x800b0001
2013-06-1211:42:58:29198013f0AU>>##  RESUMED  ## AU: Search for updates [CallId = {C2E5A5C3-EFAC-4889-889E-0BDFC048EAA3}]
2013-06-1211:42:58:29198013f0AU # WARNING: Search callback failed, result = 0x800B0001
2013-06-1211:42:58:29198013f0AU # WARNING: Failed to find updates with error code 800B0001
2013-06-1211:42:58:29198013f0AU#########
2013-06-1211:42:58:29198013f0AU##  END  ##  AU: Search for updates [CallId = {C2E5A5C3-EFAC-4889-889E-0BDFC048EAA3}]
2013-06-1211:42:58:29198013f0AU#############
2013-06-1211:42:58:29198013f0AUSuccessfully wrote event for AU health state:0
2013-06-1211:42:58:29198013f0AUAU setting next detection timeout to 2013-06-12 15:42:58
2013-06-1211:42:58:29198013f0AUSetting AU scheduled install time to 2013-06-12 13:00:00
2013-06-1211:42:58:29198013f0AUSuccessfully wrote event for AU health state:0
2013-06-1211:42:58:29198013f0AUSuccessfully wrote event for AU health state:0
2013-06-1211:42:58:3079801444PTWARNING: Cached cookie has expired or new PID is available
2013-06-1211:42:58:3079801444PTInitializing simple targeting cookie, clientId = b8ecf920-f600-4602-82fc-c64204893aa9, target group = , DNS name = machine name
2013-06-1211:42:58:3079801444PT Server URL = http://Servername/SimpleAuthWebService/SimpleAuth.asmx
2013-06-1211:43:09:7759801444PTWARNING: GetCookie failure, error = 0x8024400D, soap client error = 7, soap error code = 300, HTTP status code = 200
2013-06-1211:43:09:7759801444PTWARNING: SOAP Fault: 0x00012c
2013-06-1211:43:09:7759801444PTWARNING:     faultstring:Fault occurred
2013-06-1211:43:09:7759801444PTWARNING:     ErrorCode:ServerChanged(4)
2013-06-1211:43:09:7759801444PTWARNING:     Message:Server rolled back since last call to GetCookie
2013-06-1211:43:09:7759801444PTWARNING:     Method:"http://www.microsoft.com/SoftwareDistribution/Server/ClientWebService/GetCookie"
2013-06-1211:43:09:7759801444PTWARNING:     ID:0aea4c91-f7c5-493e-be25-389bbbc56beb
2013-06-1211:43:09:7759801444PTWARNING: PTError: 0x80244015
2013-06-1211:43:09:7759801444PTWARNING: GetCookie_WithRecovery failed : 0x80244015
2013-06-1211:43:09:7759801444PTWARNING: RefreshCookie failed: 0x80244015
2013-06-1211:43:09:7759801444PTWARNING: RefreshPTState failed: 0x80244015
2013-06-1211:43:09:8229801444PTWARNING: Cached cookie has expired or new PID is available
2013-06-1211:43:09:8229801444PTInitializing simple targeting cookie, clientId = b8ecf920-f600-4602-82fc-c64204893aa9, target group = , DNS name = machine name
2013-06-1211:43:09:8229801444PT Server URL = http://Servername/SimpleAuthWebService/SimpleAuth.asmx
2013-06-1211:43:13:5259801444PTWARNING: No updates found from server; serverID = {3DA21691-E39D-4DA6-8A4B-B43877BCB1B7}
2013-06-1211:43:13:6349801444ReportUploading 1 events using cached cookie, reporting URL = http://Servername/ReportingWebService/ReportingWebService.asmx
2013-06-1211:43:14:0409801444ReportReporter successfully uploaded 1 events.
2013-06-1211:43:14:0569801444ReportREPORT EVENT: {4B6176CC-D8F5-4385-A5B6-29C38D95E4CB}2013-06-12 11:42:58:291+01001148101{D67661EB-2423-451D-BF5D-13199E37DF28} 1800b0001 SelfUpdateFailureSoftware SynchronizationWindows Update Client failed to detect with error 0x800b0001.
2013-06-1211:43:14:0879801444ReportCWERReporter::HandleEvents - WER report upload completed with status 0x8
2013-06-1211:43:14:0879801444ReportWER Report sent: 7.6.7600.256 0x800b0001 D67661EB-2423-451D-BF5D-13199E37DF28 Scan 101 Managed
2013-06-1211:43:14:0879801444ReportCWERReporter finishing event handling. (00000000)
2013-06-1211:43:14:1039801444ReportUploading 1 events using cached cookie, reporting URL = http://Servername/ReportingWebService/ReportingWebService.asmx
2013-06-1211:43:14:1039801444ReportReporter successfully uploaded 1 events.