I did the slackbuild of libdvdcss and the win32 codecs (as root, slack 12.0) after which I could no longer startx as regular user. It finally turned out the permissions of /usr/lib, /usr/doc and /usr/include were messed up: the group and others did not have read and exec permissions anymore. I had to
Code:
chmod go+rx /usr/lib /usr/include /usr/doc
to fix the problem.
Thought I'd make this thread in case others stumble on this issue...