Hey all!! I was just going back over this as a reference, and thought that in an effort to minimize keystrokes this would perhaps be of assistance as a simple addition to the above to the very helpful aforementioned solution.

rm *.kcache
The above uses the wildcard atom '*' to leverage bash's POSIX basic regex platform into consideration. For more info check out the following man page:

man 7 regex
Additionally, issues with reference to the '/var' specific location, and I've ran live on at least 10 different computers, I.e. Dell, XPSs, HP's/etc...(I saw some below thinking their startx issues stemmed from their computer hardware/drivers). Its more of an x-org/kde config issue, as its happened to everyone I know.