We have a class infrastructure with classes consisting of "user" pc's and a single "teacher" pc. The fileserver has a folder for the teacher's "my documents", in which there are folders for each of the student users. Both types of accounts have their "my documents" redirected to these folders.
We use this nested structure so that the teacher has access to their documents in an easy way, allowing him for instance to put new shortcuts on their desktop or collect files.
The problem is that (only recently, apparently) whenever a user tries to insert files from My Documents into a powerpoint for instance it will prompt for credentials to the server. You can press cancel and re-enter the folder and it will work fine. Restart powerpoint (or whatever Office application) and you get prompted again. Apparently it's the same for their desktop, which is also redirected. Browsing to My Documents in explorer should work fine.
It's a bit vague, but the teachers aren't the best in supplying feedback. I tried to explain as best I could.
EDIT: removed link to the other issue as it was unrelated and now solved
Thanks a bunch