xdm modprobe: Can't locate module char-major-13

["jose isaias cabrera" <cabrera@wrc.xerox.com>]

Greetings!

I just installed Debian on a Dell Inspiron 7500.  It's running pretty good, 
but I loaded xdm and now it goes right into xdm and fails with the 
"modprobe: Can't locate module char-major-13" and I can't go back to the 
xterm.  It's at the xdm logon screen.

Two questions:

1. How do I stop xdm from loading at boot?

2. How do I fix this error message above?

thanks,

jose