st driver kernel panic on 4.1.1

[Pond Scum]

Ugh.  Has any had problems using the Sun st driver to control an Exabyte
8mm drive under 4.1.1?  We have no problems with SPARCstations, but on the
SPARCsystem 330 we just installed, we get kernel panics.  Here's what it
looks like:

BAD TRAP
pid 130, `tar': zero divide trap:
addr=0xf8153c00
pc=0xf80c5204, sp=0xf8268c90, psr=0x114000c6, context=0xf
g1-g7: 2800, 17f8, ffffff00, 0, f8269000, 0, 0
Begin traceback... sp = f8268c90
Called from f80907ac, fp=f8268cf0, args=f81a1448 f8268ea4 2800 f81a006c 1 1201

oeno# adb -k vmunix.0 vmcore.0
physmem	ffd
$c
_panic(0xf8112044,0xf82a2c44,0xf8103c00,0x8,0x7c152,0xf7fffba8)	+ 6c
_trap(0x82,0xf82a2c44,0xf8103c00,0x8,0x279b9db8,0x279b9db8) + 1d8
st_have_window(?)
.rem(0x2800,0x0,0x2800,0x46cd0,0x279b9db8,0x0) + 90
_stread(0xf8125850,0xf82a2ea4,0x2800,0xf8124c0c,0x1,0x1201) + cc
_spec_rdwr(0xff11d82c,0xf82a2ea4,0x0,0x0,0x2d0,0x1201) + 1c0
_vno_rw(0xf8194e38,0x0,0xf82a2ea4,0x2800,0xff11d82c,0x0) + a4
_rwuio(0xf8194e38,0xf82a2ea4,0xf82a2eb8,0x2800,0x2800,0xf82a2ea4) + 2b0
_read(0xf82a2fe0,0x18,0xf8107ac0,0xf8107ad8,0xf82a3000,0xf8107ad8) + 34
_syscall(0xf82a3000) + 3b4

The man pages say st will work with an Exabyte under 4.1.1.  What's wrong?
We can access the 1/4" tape drive fine (st0, SCSI id=4), but as soon as we
access the Exabyte (st1, SCSI id=5), it panics.  The only other thing on
the SCSI bus is a 669 MB disk drive (sd6, SCSI id=3).  We get the same
error with a GENERIC kernel or one of our own config files.

Jonathan Hue	Island Grapics Corp.	{uunet,sun}!island!hue	hue at island.com