MIT-MAGIC-COOKIE-1 Error with Control center -Please help

[Massimo TRENTO <mtrento chez com>]

hi
i think i messed up something by trying to upgrade my system to gnome
1.0.6
my original was (1.0.4 from Redhat6)
so , now when i start control center(gnomecc) or gnome-terminal from the
x terminal, i get some gtk warnings complaining about libpixmap.so not
found (but it is on my system) and at the end of the messages i get
MIT-MAGIC-COOKIE-1 authentication rejected.
segmentation fault
core dumped.

how can i resolve this ? and how can i start over with gnome without
reinstalling redhat (i don't like the hard way) I already tryed to
remove gnome packages. but after i install again gnome i get the same
error.
my system is AMD K6-2 running Kernel 2.2.10 on a Redhat 6 upgraded from
5.2
and i'm running gnome as root.

Thanks in advance.
Massimo