Fedora :: F15 Freezes On Different Hardware And Graphics Drivers?

My workplace is conducting a pilot of fedora15 for adoption as our SOE desktop. We've installed on 3 desktops and two laptops, and are experiencing an intermittent lock-up on each platform. In all cases so far over our two week trial, whilst users are performing routine work on the gnome desktop (e.g. email, web browsing, etc), the screen will freeze, and the mouse/keyboard appear to be inoperable, so it is impossible to go to a virtual desktop, etc. Only a hard reboot brings the PC back, and there are no logs, core dumps, etc.

We've been trying to eliminate sources, and have seen the fault on the following combinations:

* AMD/Intel
* A variety of graphics hardware (e.g. nvidia, intel 945)
* nvidia drivers (various versions), and nouveau
* Gnome 3 in normal and fallback mode
* rpms from the initial F15 release, and also after a full yum update (last week).

We have not been able to correlate the lock-up with particular usage patterns or system load. Sometimes, the desktop will be usable for a day or more, and other times, we may see three lockups in an hour.

There is a bug on this matter:

[URL]

I am raising the matter here to see, because I am puzzled as to why we are experiencing it on all platforms, and yet it does not seem to be so prevalent in the wider community.