zfs:lo lockup

[rondzierwa at comcast.net]

I'm running zfs on FreeBSD 7.2-RELEASE-p2. i csup'ed sys src 4 weeks ago. I have 
a 3Ware raid card with 8 1tb drives in raid5. I put the whole space in zfs as a tank and 
created several file systems from it. these are served to windoze clients via samba 3.0.34. 

several times a week i have to forcibly reset and reboot the system because one of the 
smbd processes is stuck in zfs:lo state (as displayed by "top"), and cannot be killed. 

Typically this happens when there is more than one client machine accessing the zfs 
shares. It happens when they are both accessing the same share, or different ones. 

is this something that has already been fixed? if so, what do i have to upgrade to get 
the fix? if not, what information can i provide to help somebody find a fix? 

thanks much 
ron.