I updated a couple things and may have cured that mysterious key-shortcut problem. I'm not sure, as I could never pin down what made it occur in the first place.
I also tried plugging in my external CD burner, and, lo and behold, it is now supported again. So I was able to check off another item on my con preparation list: 'CD (dual f.) with some AI files - demo, print, who knows?'
Whee!