Service pack 4 issues

We have an issue our IT department is looking at, I'm in applications, but I'm hoping maybe someone else had a similar issue.

Our .exe, .dll, .ocx, etc are stored on a central folder on the network. When an application launches a common exe is supposed to copy the modules to the user's C: drive overlaying what is already there to ensure having the latest changes. It is failing for about half of our users and we think it is a permissions problem. It seems to have started with Windows service pack 4.

Has anyone else had this issue?

http://support.microsoft.com/kb/821546/