WSUS 3.0, Several Clients dong get updates / Dont generate Reports in WSUS / Concerned Clients can access WSUS IIS / Out of proc datastore

We´ve Installed WSUS 3.0, ~120 WIndows XP Clients, All Windows XP Clients are based on the same Image. WSUS is published via GPO in AD.

Problem:

Several Xp Clients (~10 Clients ), who show up in WSUS 3.0 Dashboard, but have never created Reports nor did they get any Update at all.

I checked the windowsupdate.log on the concerned clients:


2008-11-12      11:03:10+0100       412      554      AU received event of 1
2008-11-12      11:03:10+0100       412      554      WU client succeeds CClientCallRecorder::BeginFindUpdates from AutomaticUpdates with call id {6EBB532F-55E2-438F-9EA1-FED2AB5ED4D8}
2008-11-12      11:03:10+0100       412      660      WU client executing call {6EBB532F-55E2-438F-9EA1-FED2AB5ED4D8} of type Search Call
2008-11-12      11:03:24+0100       412      660      Send failed with hr = 80072efd.
2008-11-12      11:03:24+0100       412      660      SendRequest failed with hr = 80072efd. Proxy List used: <(null)> Bypass List used : <(null)>
2008-11-12      11:03:25+0100       412      660      Send failed with hr = 80072efd.
2008-11-12      11:03:25+0100       412      660      SendRequest failed with hr = 80072efd. Proxy List used: <(null)> Bypass List used : <(null)>
2008-11-12      11:03:26+0100       412      660      Send failed with hr = 80072efd.
2008-11-12      11:03:26+0100       412      660      SendRequest failed with hr = 80072efd. Proxy List used: <(null)> Bypass List used : <(null)>
2008-11-12      11:03:27+0100       412      660      Send failed with hr = 80072efd.
2008-11-12      11:03:27+0100       412      660      SendRequest failed with hr = 80072efd. Proxy List used: <(null)> Bypass List used : <(null)>
2008-11-12      11:03:27+0100       412      660      DownloadFileInternal failed for http://server1234:8530/SelfUpdate/wuident.cab: error 0x80072efd
2008-11-12      11:03:27+0100       412      660      IsUpdateRequired failed with error 0x80072efd
2008-11-12      11:03:27+0100       412      660      OS Version = 5.1.2600.2.0.65792
2008-11-12      11:03:28+0100       412      660      Computer Brand = Dell Inc.
2008-11-12      11:03:28+0100       412      660      Computer Model = Latitude D630                  
2008-11-12      11:03:28+0100       412      660      Bios Revision = A03
2008-11-12      11:03:28+0100       412      660      Bios Name = Phoenix ROM BIOS PLUS Version 1.10 A03
2008-11-12      11:03:28+0100       412      660      Bios Release Date = 2007-07-23T00:00:00
2008-11-12      11:03:28+0100       412      660      Locale ID = 1031
2008-11-12      11:03:28+0100       412      660      ClientVersion: iuengine.dll = 5.4.3790.2180
2008-11-12      11:03:28+0100       412      660      ClientVersion: wuapi.dll = 5.4.3790.2180
2008-11-12      11:03:28+0100       412      660      ClientVersion: wuauclt.exe = 5.4.3790.2180
2008-11-12      11:03:28+0100       412      660      ClientVersion: wuauclt1.exe = 5.4.3790.2180
2008-11-12      11:03:28+0100       412      660      ClientVersion: wuaucpl.cpl = 5.4.3790.2180
2008-11-12      11:03:28+0100       412      660      ClientVersion: wuaueng.dll = 5.4.3790.2180
2008-11-12      11:03:28+0100       412      660      ClientVersion: wuaueng1.dll = 5.4.3790.2180
2008-11-12      11:03:28+0100       412      660      ClientVersion: wuauserv.dll = 5.4.3790.2180
2008-11-12      11:03:28+0100       412      660      ClientVersion: wucltui.dll = 5.4.3790.2180
2008-11-12      11:03:28+0100      1200      ed4      Trying to make out of proc datastore active
2008-11-12      11:03:29+0100      1200      ed4      Out of proc datastore is now active
2008-11-12      11:03:29+0100       412      660      PT: Using serverID {3DA21691-E39D-4DA6-8A4B-B43877BCB1B7}
2008-11-12      11:03:29+0100       412      660      WU client failed Searching for update with error 0x80248008
2008-11-12      11:03:29+0100       412      660      Search Callback Failed, hr is 0x80248008
2008-11-12      11:03:29+0100       412      660      Setting next AU detection timeout to 2008-11-12 15:03:29
2008-11-12      11:03:29+0100       412      660      Setting AU scheduled install time to 2008-11-12 22:00:00
2008-11-12      11:03:29+0100       412      660      WU client calls back to search call AutomaticUpdates with code Call failed and error 0x80248008
2008-11-12      11:03:29+0100       412      660      WU client completed and deleted call {6EBB532F-55E2-438F-9EA1-FED2AB5ED4D8}
2008-11-12      11:03:33+0100       412      660      REPORT EVENT: {5AD0DD13-5C11-4262-9BB4-F730DA8E63D3}      2911      2008-11-12 11:03:27+0100      1      148      101      {D67661EB-2423-451D-BF5D-13199E37DF28}      0      80072efd      SelfUpdate      Failure      Software Synchronization      Error: Agent failed detecting with reason: 0x80072efd
2008-11-12      11:03:33+0100       412      660      REPORT EVENT: {A2780378-0D49-4453-A2A4-39040392AC71}      2912      2008-11-12 11:03:29+0100      1      148      101      {00000000-0000-0000-0000-000000000000}      0      80248008      AutomaticUpdates      Failure      Software Synchronization      Error: Agent failed detecting with reason: 0x80248008
2008-11-12      11:03:33+0100       412      660      Created new event cache file at C:\WINDOWS\SoftwareDistribution\EventCache\{809D01A7-86AB-4F2F-8B72-B36F6DC3A65B}.bin for writing.
2008-11-12      11:03:33+0100       412      660      Reopened existing event cache file at C:\WINDOWS\SoftwareDistribution\EventCache\{C1F48775-C7E3-4919-90FF-B1EF2465CC55}.bin for writing.
2008-11-12      11:05:34+0100       412      ad8      Triggering AU detection through DetectNow api

When i manualy enter the http://server1234:8530/SelfUpdate/wuident.cab adress within IE, it perfectly downloads the File.

whats wrong ? its on ~10 Windows XP Clients out of 140.