'wrong pmg' error

[carlo at cvs.rochester.edu]

I am having some problems with my Sun 3/160C running OS 4.0; I can't
even figure out where to start looking, so I wonder if someone might
have seen this before and can give me some pointers.

The problem is the following: for some inexplicable reason, seemingly
unrelated to what I am doing on the machine, but most likely when the
load is high (2-4), the machine crashes, with the following error
messages:

vmunix: panic: wrong pmg
vmunix: syncing file systems... [5] [5] [4] [2] done
vmunix: dumping to vp f22ba8c, offset 36688
vmunix: 1022 total pages, dump succeeded
vmunix: rebooting...
etc.

What/who/where is 'pmg'? What's happening? What shall I do?

Thanks in advance for any help,
Carlo Tiana.
carlo at cvs.rochester.edu