More timeout problems :(

[Alex]

Hi:

I just recently was doing some fairly disk intensive work (rebuilding the
man pages, building kde, and just finished running make clean on
/usr/src, and closing a mailbox in Pine), when Pine alerted me to a disk
error, so I switched over to ttyv0 to see screenfulls of sd0 timeout.. sd0
no longer timedout... sd0 timedout while recovering.. then sd1, then sd0
again, etc, etc.  I'm running FreeBSD current sources were just
cvsup'd last night, kernel is about a week old.  This is the first time
I've ever had probelems with my disks (two Quantum narrow, one ultra, one 
fast scsi on an aic-7880).  The longest the system has been up was 21
days, no problems at all then.  After about twenty minutes, things started
to want to use the disk, so the swapper faulted, and just about everything
besides pine that wanted to write to the disk segfaulted.  I went into the
kernel debugger, and panic'd the kernel.  Going into the SCSI Select
"program" and disabling WIDE negotation worked, probing the scsi bus froze
the computer.  Power cycle followed.  I do have SCB paging, tagged
queuing, and memio enabled.  My question is this, is there any
way to prevent this from happening again (luckily this time I didn't loose
any data), if not how much does an NCR/Symbios 810 cost?

- alex