Lest we forget where this all began...
So I finally got my AirPort Express to join my 2.4 GHz FiOS network, and as you said it should, AirPlay worked, but if I used the 2.4 GHz band for Internet at the same time, playback was choppy and subject to drop-outs; using the 2.4 GHz network for AirPlay and the 5 GHz network for Internet worked fine.
Unfortunately, though, no matter what I tried, including deleting and reinstalling drivers, I couldn't get the Bonjour printer to print..."Connection Error", regardless of which network I was using for Internet, and despite the fact that I deleted the USB printer before installation, and all settings looked correct.
Unless you've got any ideas, I"m throwing in the towel, because at this point my problem could be with my base station.
Many thanks for all your help. (At the very least, I learned a bunch - well, a little, anyhow - about networking.)
