We too have been plagued by a few servers having these issues. Thought we had this resolved by shutting off DEP (Properties of My Computer, Advanced, Performance Settings, DEP, and then set to essential Windows programs) -- nope that didn't do anything but make Windows even angrier! For now we have rolled back and patched to the latest and greatest, but this is truly another magnificent piece of work from MS to release something that breaks your existing environment. The only good thing that I can say is that new servers that are rolled with SP1 don't show these signs. I wonder if you can apply SP1 to an existing machine, go into Add/Remove, select 7.5, tell it to reinstall if it will overwrite the security settings in the registry along with preserving your existing setup? Gotta run ladies and gents....gotta do some testing.