Bug 74182

Investigating in an wierd error behavior of a FreeBSD 5.3 box with SMP I found out that PCI VGA graphics cards seem to trigger those problems I reported.
I use a ASUS CUR-DLS mobo with two P3 at 1GHz, 1GBytes RAM, U160 SCSI equipment and built in 4MB ATI Rage XL PCI graphics. Problem was: Machine freezes spontanously in SMP mode, especially doing a lot of graphics output or simply using Mozilla/FireFox intensively. 
In single user mode (for update and upgrade purposes) the console freezes after doing a lot of output (while showing what' getting compiled or installed).
This 'freezing' does not occur using a Matrox Millenium II PCI! Single user mode works great and stable - but I can not boot machine in multi user mode anymore, the console get stuck with a blinking cursor. That is really weird and seems to be a software problem. Disabling SMP keeps the system running for days with the built in ATI Rage XL PCI graphics, but it still breaks single user mode! I ran into harsh situations while trying to do a buildworld and getting stuck due a dying system when libs got installed!
SMP brings down the machine very rapid when doing a lot of graphics!
Changing to a Matrox Millenium II, 4MB PCI graphics card keeps single user mode working but freezes the box when coming up into multi user mode! Machine get stuck with a blinking green carret but is still responsive via network.

How-To-Repeat:       Use FreeBSD 5.3-RELEASE  with PCI graphics and SMP!