SCSI card problems

We have been having trouble with a SCSI card that was attached to a tape drive that was installed on a CommVault Media Agent server. The card was brand new and the drivers were Windows 2k3 certified. We started having issues with this server during the CommVault install. The server would just spontaneously reboot leaving the CommVault backups in disarray. Troubleshooting led us to update the firmware on the card, the tape library firmware & driver, and the tape drive firmware & driver. This fixed the problem for a few days and it would happen again. It would only happen when doing an auxiliary copy from disk to tape. After some deep-dive troubleshooting on the SCSI I/O bus, we were able to get some logs during the time immediately before one of the spontaneous reboots/failures. From the logs we were able to find that the card actually had some type of problem that caused extended I/O latencies during periods of high traffic (aux copies). We ordered an Adaptec card and installed it. Now, not only are copies to tape 2x faster, it hasn’t crashed . . . yet.