xserve raid will not see replaced drive module

I have an Xserve RAID with 7x750 RAID5 on the Upper Controller. I noticed that Drive #5 had an amber light and RAID admin reported that the RAID was degraded.

The Xserve RAID has Firmware version 1.5.1/1.5.1c

After making a fresh complete backup of the data, I hot-swapped the drive with a spare ADM I purchased at the same time as the Xserve RAID.

The new Module/Drive also displays an Amber light on it's handle.

RAID Admin under "Arrays & Drives" shows a Status of "Not Installed" for the Drive.

If I select Utilities > Make Drive Available for Use, the description box shows the slot as "Drive Bay 5 is empty."

Even though both controllers report a status of OK, I tried powering down the system and swapping the controllers (the Lower Controller also has a 7x750 RAID 5). Drive bay 5 still displays amber. Drives 8-14 all display green. I think I can eliminate a conrtoller issue.

As the Upper RAID is live data and the lower RAID is for disk-to-disk backup of the upper, I may try hot swapping a known good ADM on the lower side for my spare ADM. This should result in the lower RAID being rebuild with the new ADM, confirming that the module is indeed good? That sounds risky, would anyone recommend that?

Is there anything further I can do to try and incorporate this drive into my RAID set?

Is it likely that I've had a bad ADM sitting as a reserve for the past 4 years? Should I try to replace the drive in the module?

Any suggestions or advise would be greatly appreciated.