As some of you have already discovered, ConfigMgr (RTM and SP1) is unable to capture an image of a Windows Vista SP2 or Windows Server 2008 SP2 operating system.  Fortunately, there are now two hotfixes available for this, one if you are running ConfigMgr RTM:

http://support.microsoft.com/kb/969991

And another if you are running ConfigMgr SP1:

http://support.microsoft.com/kb/970093

This fix is already included in the ConfigMgr SP2 beta (which is available from Connect now), but that’s not supported in production environments.