repeatable ZFS panic: share->excl

Hi,
   Just started to experiment with 8-CURRENT and zfs, after having a 
FreeBSD 7, ZFS server for about 18 months now.
   First problem I notice is a panic, which seems to occur every time 'tar' 
is used. Might be unrelated to tar, but it definately provokes it. Simply 
the tar command or a pkg_add causes it.
   Sorry I don't have a serial console, but here's a picture of the screen:

http://www.rootshell.be/~msp/IMG_4002.JPG

   I initially had a zfsbooting root, from a CF, plus a RAIDZ2 on HDD. 
Everytime I tried to perform a pkg_add I would get this panic. I then 
moved root to ufs and the pkg_add would then not cause the panic. However, 
any tar which accessed the zfs raidz2 pool still causes this panic.
   Is this known? I couldn't see the same reported anywhere, so forgive me 
if I have missed it.
   Please let me know if you need kernel config, etc. to debug this 
further.
   Cheers.

-- 
Mark Powell - UNIX System Administrator - The University of Salford
Information & Learning Services, Clifford Whitworth Building,
Salford University, Manchester, M5 4WT, UK.
Tel: +44 161 295 6843  Fax: +44 161 295 5888  www.pgp.com for PGP key