startx will start X with fvwm but not gnome help

[NVangogh]

I have searched the net but cannot find an answer for this.
I have the latest xorg server pkg installed and configured x11. I have
the correct driver installed for my system chipset.: xf86-video-intel. I
am guessing the problem is not with my xorg.conf [cause fvwm works & the
problem is also repeated on another pc of mine]

The problem is that I cannot seem to startx with any wm other than fvwm
(this is fine, but i prefer gnome).

this is what i have tried

1. I have followed the standard procedure: echo "/usr/local/bin/gnome-
session" > /home/mydir/.xinitrc. On re-booting i try startx and get the
error i830 Vblank pipe setup failed 0. - x will not start at all.

2. alternatively - in /etc/rc.conf  gnome_enable="YES".
The very first time i booted with this, it worked. The next day (today) I
tried to boot and got the gdm login screen. After entering my details,
the gnome splash screen appears..but it seems to hang. I left it and it
was like this for nearly 15 minutes. Eventually my desktop appeared - but
everything was sluggish & some progs would not start eg i could not even
open a terminal. After a while the session just terminates and causes a
re-boot. I have tried this twice and the same thing happens.

3. Instead of gdm, i have also used the kdm and got the same problem.


Anyone please assist with this problem?  
(To run gnome, i have to startx -which starts with with fvwm -then run a 
gnome-session from a aterm console. this is burning up my limited 
resources and of course all windows open in the fvwm style which is not 
ideal.