FreeBSD 9.0-beta2 can't reboot with ZFS raidz2

Hi,

My FreeBSD box (amd64, beta2, raidz2 on three disk) can't reboot after
syncing buffer stage:

http://www.scrnshots.com/users/subbsd/screenshots/293839

Also i got this issue on 8-disk system (GPT/ZFS).

With UFS filesystem all ok on the same hardware