Not sure whether this is really a NetBSD problem or not.
I have an Orchid Kelvin 64 VLB video card (Cirrus Logic 5434 chipset, 2M)
After running X for some period of time, the machine locks.  Am not sure
just how it's locking.  If I start the XF86 3.1.2 SVGA server in -bpp 32
it won't even get through drawing the stippled background.  If started
in -bpp 16 it will lock before bringing up the WM.  To make it lock in 8bit,
sufficient graphical activity is required.  Usually some animation helps.
I'm wondering if this is a misfeature of the 1.1 or later kernels.  Used
to run rock solid on older kernels in X.  Haven't run X for a while tho.
Machine is as follows:
AMD 486 dx4/100
16M core
aha 1542cf
quantum 730M scsi-2, toshi 2x cdrom, iomega zipdrive
usr sportster 14.4, generic IDE card for serial and parallel.

I tried swapping the machine to death to see if it was a SCSI or swapping
problem, but it just killed the processes when it ran out of swap.  :)
Any advice/comments/whatever are welcome, as I'm stumped.