FreeBSD 8.3 may have updated drivers that *might* help. FreeNAS 8.2 will update its base to FreeBSD 8.3 some time in May. If you know how, you could possibly build the driver from that source. There's a good chance if the problem has been fixed there that the driver should work with this version of FreeNAS. I'm sorry, I'd offer to build it and post it but I've got a bit of a full plate.