Our Sun 4/60 seems to be crashing mysteriously

[Bill Thomason]

Below you will find a portion of /usr/adm/messages from our Sun 4/60.  We
can't determine the reason for the crash and were wondering if anyone out
there has seen this situation and found the cause of the crash.  This has
happened twice about a month apart.  Below is the message from the first
time.  The second time the messages are the same except the amount of
traceback is considerably larger.

Thanks
-bill

=============================================================================
Feb 14 16:48:27 zeus vmunix: BAD TRAP
Feb 14 16:48:27 zeus vmunix: pid 3104, `csh': Data fault
Feb 14 16:48:27 zeus vmunix: kernel read fault at addr=0xf8194fb4, pme=0x0
Feb 14 16:48:27 zeus vmunix: Sync Error Reg 80<INVALID>
Feb 14 16:48:27 zeus vmunix: pc=0xf80ddcfc, sp=0xf8115ae0, psr=0x801ac5, context=0x0
Feb 14 16:48:27 zeus vmunix: g1-g7: ff0561c0, f8130000, 801ae6, 80, f822b000, f8138000, f8138400
Feb 14 16:48:27 zeus vmunix: Begin traceback... sp = f8115ae0
Feb 14 16:48:27 zeus vmunix: Called from f80dda9c, fp=f822ae98, args=f8167128 ff001e3c 300 18 18 1
Feb 14 16:48:27 zeus vmunix: End trace