I am seeing the same problem using a single server (Sun Solaris 10) attached to an iSCSI SAN.
It seemes to panic under heavy iSCSI I/O, like during backups using Backup Exec RALUS client version 7170.
Just wondering if you have resolved you problem?
Has any one solved this problem. I am seeing the same issue on my solaris 10 sparc system that is attached to EMC Clariion disks.This seems to have been out there since last year. Please explain how you fixed it.