I don't know if this is really worth reporting or not but I have a
DecStation 5000/125 that was up over 101 days (without a UPS, even!).  It
just crashed today, the screen says

trap: bus error (load or store) in kernel mode
status=0x8fc34, cause=0x1c, epc=0x80155364, vaddr=0xc0081f70
pid=5372 cmd=sh usp=0x7ffff600 ksp=0xcd9fad30
Stopped in sh at  pmap_enter+0x1e4;   lw      v0,12(v1)
db>

        It's got 120M of RAM and is running 1.41.  It's got the 5.7j PROM.
The machine was idle at the time as far as I know.

GZ