upgrading to gtk 2.6.1 problem ( starting X server)

[mohair crackus <elcracker gmail com>]

Hello,
Any help would be appreciated. Problem:
I have redhat enterprise 3 ws insalled.  running gdm - gnome 2.2.0 was
initially installed.
I upgraded to gtk 2.6.1 and it installed fine.
However, when i rebooted and the x server started, i get a message
saying that there is already an x server running on display :0.  But
if i killall X and start kdm, or boot in init 3 and type startx i can
log in and run gnome.
Does anybody have any iddeas thanks in advance.
Mark