The problem is one of Microsoft's recent April 2007 Patches:
KB925902 (MS-07-017)
If you uninstall this patch, the problem will subdue, but you're still vulnerable and will continue to be until Microsoft comes out with a fix.
Note: This was the patch Microsoft initially came out with on Apr 3rd and then re-issued again on Apr 10th because of bugs, so apparently a NEW (yet to be released) patch for the Apr 10th patch of the Apr 3rd patch is still required if/when they ever release it!
