Odd system failures

[560SL]

Been having these really strange system failures since
my last 3.9 installation about a month ago.

I was hoping some of you may have a clue on whats wrong.

My system is A4000T, CSPPC 604/233 060/64 128Mb, with
mediator Voodoo 5500, Delfina DSP.

My system is a clean install from 3.1 to 3.9 with both
boing bags. I did change the powerpc.library to the
"de Ville" version (16.1 beta).

System failures consists of random craches (hangups),
which seems to happen when resizing windows, requesters
are being opened etc. Typically, choosing "Load Image"
in ppaint, then everything just dies.

Other symptoms, gears demo dies after ca 15 mins.

Any idea if I missed a must-have patch out there
somewhere?

System is pretty much useless with this behaviour.
Any help is appreciated.

[560SL]

Happens only with 3.9.
3.1 is rock steady.

[560SL]

mmu variable is set to 'no'. I checked that.

What versions of 040/060 libs should I use? I havent checked those, i assumed the correct ones were installed with 3.9.

The Voodoo is connected to the power supply in the A4000T, ie with standard HD/CD-rom/etc type of power cables. No separate power supply.