Took me a while to find that darn shadercache folder. It is in the Planeshift user settings folder, not the client folder. You may have to turn the hidden files/folders off to find it. Should be in your /home/[user]/.PlaneShift folder, same place as the log files and screenshots. I was having issues in my Ubuntu 64 bit client, couldn't find a fix, so went to my Vista 64 bit install, and it is much better. I'll test out completely deleting that folder, I just wiped out all the files in it and that didn't seem to help. Would have the same issue, locking up, not crashing, just couldn't move or do anything for a long time.
Thanks -stf-. That was it, the shadercache.zip file was not being created when the shadercache folder was still there. I think I just glazed over what you typed earlier since I had no idea what was going on and what a shadercache thingee was to begin with.