If anyone has any experience troubleshooting FC connections with Emulex HBA cards I've got a XenServer 5.6 system that runs everything and can't stay working for more than a day.

From the kernel log:

Sep 17 17:52:25 xenserver02 kernel: lpfc 0000:15:00.1: 1:0459 Adapter heartbeat failure, taking this port offline.
Sep 17 17:52:28 xenserver02 kernel: lpfc 0000:15:00.0: 0:0459 Adapter heartbeat failure, taking this port offline.

Basically the storage disconnects, this happens on both physical servers and we've elimanted all other hardware, looking like a driver issue or a firmware issue on the HBAs. On the off chance that someone reading this knows a lot about Emulex HBAs running on Linux, I'd appreciate any help or suggestions. Thanks.