When I plugged the AES output from the RayDAT card into the supposedly empty eighth AES slot on the digital patch bay, I found that something else was already there. Hmm. The slot was unlabeled according to my P-touch labels on the rack, so I pulled the cables and figured I'd sort it out later.
Later, I realized those were the inputs from the mic-pre in the studio room, which I use when recording by myself. Oops. I guess I'll need to plug those back in.
There was one SPDIF port left open on the patch bay -- the last port open on the 16-channel patch bay! -- and there was a piece of gear that I had been sending in via AES that could go in via SPDIF, except I had no spare SPDIF cables. So I bought a couple of SPDIF cables (as daisy_knotwise has said, the problem is not the digital gear, it's all of its little digital friends and relations) and crawled back underneath the console to move that piece of gear from position 7 (AES) to position 14 (SPDIF). Then I could plug the mic-pre back into position 7 where it resides happily next to the other matching mic-pre in position 6.
As long as I was flat on my back, I swapped the SPDIF I/O for the RayDAT card from position 12 to position 9, which left it sitting one click of the knob away from the RayDAT's AES I/O in position 8. This is convenient, because I can leave position 8 assigned to Cubase and position 9 assigned to Wavelab and the two programs won't fight with each other for control of the digital world. :)
So the digital patch bay now looks like this:
1: (AES) ADAT <-> AES channels 1 & 2
2: (AES) ADAT <-> AES channels 3 & 4
3: (AES) ADAT <-> AES channels 5 & 6
4: (AES) ADAT <-> AES channels 7 & 8
5: (AES) mixer digital mix I/O
6: (AES) mic-pre control room
7: (AES) mic-pre studio
8: (AES) RayDAT AES I/O
9: (SPDIF) RayDAT SPDIF I/O
10: (SPDIF) lesser TC reverb
11: (SPDIF) DAT player
12: (SPDIF) lesser Lexicon reverb
13: (SPDIF) better Lexicon reverb
14: (SPDIF) TC mastering box
15: (TOSLINK) TC Intonator
16: (TOSLINK) better TC reverb
We'll see how long this configuration lasts. :)