SunOS 4.X client node wierdness - help!

[Operator]

This is another one of those last ditch pleas to the net for help.
Normally we can troubleshoot most problems, or worst case get help from
Sun. Both have failed in this case...

Symptom:	Four Sun 3/75 8meg clients off a 4meg 3/180 server 
		running SunOS 4.0.3 have all sorts of wierd errors where
		suddenly trying to run utilities such as consoletool,
		a compile, mail, just about anything causes a core
		dump (illegal instruction), undefined routine in
		ld.so, etc. Also, sometimes the server crashes with
			panic: free: freeing free frag   or
			panic: ifree: freeing free inode
		with the block listed almost always #32, one of the
		duplicate superblocks. Massive fsck(8)'s follow,
		with many lost files. Sometimes just rebooting a
		client node fixes it, sometimes not.

History:	Never had a problem like this before SunOS 4.X upgrade
		about 3 months ago. All server hardware involved has
		been replaced except the backplane and power supply.
		Hardware diagnostics check out ok on server & clients.
		Originally we were running 4.0.0, and Sun informed us
		that there was some issue with the 4.0.0 formatter, so
		we reformatted the disk under 4.0.3 to no avail. Sun
		also indicated that we are running the 1.2gig Hitachi
		DK815 drive, which few sites have and they may not have
		QA'd this drive in a SunOS4/Sun-3 server environment.

If anyone out there in the trenches has fought this battle, please
send me email about what you found out. Thanks!

Jim Morton, APPLiX Inc., Westboro, MA
...uunet!applix!jim    jim at applix.com