Last time someone had a similar-sounding problem, it was because they had something in their .tcshrc that failed when the current working directory was not the home directory. The easy way to test for this is to rename your .tcshrc so that tcsh can't find it, and see if the problem goes away.
If that works, go through your .tcshrc and try to find the mistake. If you can't, then post it here, and I'm sure one of us will be able to help.
Robin