Like it says on the tin. Since yesterday evening, I've been unable to log in graphically as a regular user though root can do so successfully (if you log in as a user the screen goes black and cycles back to the login screen). I'm assuming I hosed something last night though I was only messing with a DVB stick and was installing patch-utils etc I can't think of anything that would cause the problems I have.
I can log in graphically as root, and can su to a regular user. All files are still there but although I can successfully run ls, cd, vi I can't run vim, mc, pine, opera and mplayer (says command not found).
If I su to a regular user it doesn't appear that I can su back to root. I may be typing the password wrong, but doubt I could consistently make the same error.
The path env variable for users seems very short comparing to root's env variable.
naturally if I then su (from root - can't do it from a regular user account) the path variable reduces considerably since it's not reading the full environment.
I added a new user, and it seems to come encumbered with the same problems. My guess is that I'm looking for a path/permission issue here as I think the lack of login is no more than a symptom of x not starting (startx manually results in "command not found") and various programs not starting is likely to be as a result of path/permission if it works fine for root.