I have 2 users that have installed SP2 on their GX270SFF machines. 
Both are now having problems with their PC's locking up.
The machines will run for some time and then the screen will go blank and the CD-Rom light will go on,
it almost looks like it's trying to reboot, but locks up  The user unplugs the machine to get it to come back on.

We run Symantec AV Corp Edition and they have been scanned with the latest Virus Definitions
I have also scanned them for spyware with Ad-Aware.
I installed the latest video/network/bios updates and uninstalled any Dell utilities.
This helped, but the machines still lock up at least once per day.

Other GX270's non-SFF along with GX240/260's and an off brand laptop are running SP2 without problems.

Is anyone else having a problem with SP2 and the GX270SFF?
If not, I'll just uninstall SP2 to see if the lockups stop.

I opened a support ticket with Dell.
The technician had me to run the complete diagnostics, which came up with no errors.

Thanks in advance for any information.

Steve