Biztalk Server and Windows Server 2003 Service pack 2

i faced today a weird problem with the installation of Biztalk Server...

After installing BizTalk server 2006, I configured both “Enterprise SSO” and “Group” Successfully.
When trying to configure “BizTalk Runtime”, it fails with the following error:

“Could not deploy 'Microsoft.BizTalk.KwTpm.StsDefaultPipelines' on computer 'WS2003-VM-03'. Please check if BizTalk is installed correctly. (SeedCfg)”

I tried un-install then re-install BizTalk server and still getting the same error.

Here is my configuration:
OS: Windows 2003 Server + SP2
BizTalk Server 2006 – BizTalk databases are on remote SQL Server.

the problem was fixed when i installed the Biztalk Server on a Windows 2003 with SP1 .. it seems like there is something with SP2 that couldn't register that assembly..

Cheers ,,

Ahmed