Hoping some one can save me hours of messing around on this bizarre issue. I am running Slackware64 13.34 (I think), xfce version 4.6.2. I have a few panel icons and for no apparent reason yesterday when I logged in they had all been replaced by a nice little "box of crayons" icon with no associated application. I changed them back to my original config, thunderbird, firefox, etc. and thought nothing of it only to find they get rewritten back to "box of crayons" on every restart.
Heaven only knows how this has come about as I've changed nothing and the system has been fine for months.
Any ideas where I need to look?
The first thing to try is to clear your sessions cache. The best way to do this is to delete $HOME/.cache/session when you are not logged in (note: this will delete any saved sessions you may have).
You might also want to have a look at some log files to see if there are any hints. Perhaps $HOME/.xsession-errors (if Slackware uses it) or any other place where user-based X errors are logged.