can't run X as user

[Brian Stults <bstults@crim.ufl.edu>]

Hello,

I posted this message twice to debian-user, and searched all over the 
internet.  Having not found an answer yet, I am reluctantly posting the 
question here.  Sorry to bother, but I am at a dead end.

I know I've seen this before, but I cannot find the solution anywhere. I 
recently re-installed sid to an empty partition.  I can run X as root 
just fine.  But when I try to run it as a user, I get the following 
errors in /var/log/XFree86.0.log:


(WW) xf86ReadBIOS: Failed to open /dev/mem (Operation not permitted)

Fatal server error:
xf86OpenConsole: Server must be suid root


I have a couple of other systems working fine, so I tried to duplicate 
file permissions and other things, but it still doesn't work properly. 
Here is some info:

XFree86 Version 4.2.1.1

hardin:/usr/X11R6/bin# ls -l X*
-rwsr-sr-x    1 root     root         7476 Aug 29 11:30 X
-rwsr-sr-x    1 root     root      1584152 Aug 29 11:30 XFree86
-rwxr-xr-x    1 root     root        27494 Aug 29 11:26 Xmark

hardin:/dev# ls -l mem
crw-r-----    1 root     kmem       1,   1 Aug 29 21:51 mem

hardin:/usr/X11R6/bin# cat /etc/X11/Xwrapper.config
allowed_users=console
nice_value=-10


I can't think of anything else to mention.  Any suggestions?

Thanks.