I'm currently configuring SCCM 2007R3 but i've hit a problem with syncing WSUS

I'm getting the following error when trying to sycnronise:
Code:
Severity	Type	Site code	Date / Time	System	Component	Message ID	Description
Error	Milestone	ARC	08/07/2011 13:33:04	CASPER	SMS_WSUS_SYNC_MANAGER	6703	 SMS WSUS Synchronization failed.   Message: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.   Source: Microsoft.SystemsManagementServer.SoftwareUpdatesManagement.UpdatesManager.UpdatesManagerClass.DefineCategory.    The operating system reported error 2147500035: Invalid pointer
Google isn't much help with this one.

Anyone here have any ideas?