Dropped connection to Brocade 4/12

[Havard_3]

Hi,

Small problem I hope someone can shed some light on ...

First of a short summary of the system I'm having problems with;
1 HP c7000 w/assorted blc's
1 HP EVA 6000 w/some disks
1 HP MSL 6030 w/2x Ultrium 960's
2 HP Brocade 4/12 SAN switches
1 Dell 1750 w/Emulex FC controller (not my choice and plan to migrate to a ProLiant, but oh well).


The Dell server is used to manage the above mentioned system, and is also used as a backup server running Backup Exec v12 with options.
The server is connected by fiber cable to both Brocades.

Now onto the problem;
A couple of days ago the backups started failing as the drives went offline.
First port of call was a reboot, and the same night the backups rans ok.
However, the next night it came back and has more or less stayed that way since.
Spent an hour or so trying the usual Symantec KB troubleshooting tips but no luck.

So I started looking around the system more in depth and when I looked at the FC controller, I found that it had lost connection to one of the Brocades - more specifically the one which the MSL is connected to.
I shut the server down along with the MSL, and disconnected/reconnected the FC cables. Then powered everything back up in order while looking at the server console. First brocade connection came up OK, but not the one with the MSL.
Rebooted server again, and this time everything got connected. Tried running a backup, which failed after 1 hour and 58 minutes. Same problem, disconnected from the brocade.

So far I've updated the firmware on the MSL, and re-installed Backup Exec along with the FC controller driver+software.
I have not taken the step towards updating the firmware on the controller.
As far as I can remember, the server has not been updated with anything apart from EVA management software in the last couple of months.

I have attached a view from HBAnywhere showing what it looks like when the link drops.

Anyone got an idea as to what can cause this issue - faulty fiber cable, controller?

TIA