PROBLEM Logon has obnoxious new pause, 2 users can't login.

[Pyromunky]

PROBLEM. Strange pause/black screen and erratic logins. PLEASE HELP

Mandrake 10.1 dual booting, running both KDE and Gnome

this is A result of my exploring to learn Mandrake, that I already know.
I was messing around with adding a couple users, and trying to give permissions to the two existing users to be able to add files to the community wallpapers folder usr/share/wallpapers/ and now somethings have changed:

when logging out or in, there is a 30-120 second pause of black screen before the logon menu comes up, the two old users cannot have their icons changed, the two new users when logged into fade to black screen, and then come back to the logon menu. and the process XFS now claims 70-90% CPU usage. What have I done? where to start? Thank you.

[Pyromunky]

Please oh please, does anyone know what might be happeining? Should I reinstall Mandrake? Is there something else I can do, or some file to check to find out what I may have changed? Is my computer just doing that blasted I'm-possessed thing they do sometimes? Any help is appreciated, I am definitely new to Linux and I won't go back... to the bad place..