I think it's another one of those WTF? moments.

I am not joking, I touched NOTHING, and this morning I stuck in a new disk for it to RIP, and BINGO! It got all the outstanding albums except one, and started RIPping the new disc with the correct track details.

I give up - I feel sure that this BBS is magic. So thanks to Tony for resetting the Internet again, and Gracenote for resetting CDDB lookup

I really don't know what happened, and I have touched neither cabling nor settings - yet now it's working again. I give up.

Thanks for your patience, and - good suggestions in case it happens again in the future. Thanks, people!