Fedora xen - Feb 2007 - Strange video problem with Xen kernel and undocked laptop

Computer:   IBM T43
kernel:    2.6.19-1.2895.fc6xen

When docked, the laptop seems very happy, and I can use X/Gnome/etc fine 
... undocked, the entire screen goes black right after logging in via 
gdm and I can''t even switch to a tty.   Booting a non-Xen kernel allows
full use of graphics, and I can find no relevant enteries in 
/var/log/xen/* that indicate what might be going on.

Any ideas or has anyone else experienced similar?

--Michael

Michael DeHaan wrote:
> Computer:   IBM T43
> kernel:    2.6.19-1.2895.fc6xen
>
> When docked, the laptop seems very happy, and I can use X/Gnome/etc 
> fine ... undocked, the entire screen goes black right after logging in 
> via gdm and I can''t even switch to a tty.   Booting a non-Xen
kernel
> allows full use of graphics, and I can find no relevant enteries in 
> /var/log/xen/* that indicate what might be going on.
>
> Any ideas or has anyone else experienced similar?
>
> --Michael
>
>
Graphics card, if it helps...

[root@mdehaan service]# /sbin/lspci | grep ATI
01:00.0 VGA compatible controller: ATI Technologies Inc M22 [Radeon 
Mobility M300]