Unfortunately the video still died and the acpi=off option did not fix the problem. The type of video card is an Embedded ATI Rage XL with 8MB memory (straight from the Dell poweredge 700 specs).
I scoured the logs and found this in /var/log/gdm/:0.log
X Window System Version 7.0.0
Release Date: 21 December 2005
X Protocol Version 11, Revision 0, Release 7.0
Build Operating System:Linux 2.6.9-34.ELsmp i686Red Hat, Inc.
Current Operating System: Linux mailserv.iii.net.au 2.6.18-1.2257.fc5smp #1 SMP Fri Dec 15 16:33:51 EST 2006 i686
Build Date: 09 January 2007
Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
Module Loader present
Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Mon Feb 26 08:47:04 2007
(==) Using config file: "/etc/X11/xorg.conf"
FATAL: Module mach64 not found.
[drm] failed to load kernel module "mach64"
(EE) ATI(0): [dri] DRIScreenInit Failed
All these messages are present on bootup and before the video crashes.
Since its a onboard video card I thought I'd check the BIOS version, the machine is running Dell's A00 and there is a A06 version available off dell.com.
I have applied the BIOS upgrade and will see how that goes, I have removed the acpi option as well...