Thanks for all the help and advice.
I finally got in touch with Slim Devices tech support last night. They were closed during the long weekend and I was busy Tuesday evening -- one thing I learned from all this is not to have Sqeezebox problems on the Friday night of a long weekend. It took the tech no more than 5 minutes to get me back up and running. I asked him if it was always that easy, and he said, "Yup."
The problems were that the router had burped for some unknown reason and lost most of my settings and that I had then screwed up in my solo attempts to fix things. My final hangup was that, when my Squeezebox would ask for my network password, I kept trying to use the local network password rather than the password I used to reestablish WPA Personal encryption. In my defense, the former is called a "password" in the Linksys set up site, while the latter is called a "key."
Anyhow, it's great to have the SB back. Mine is a Red Wine Audio modded SB3 and its sound is sooo much better than my decent, but not great CD player (NAD C542).
Thanks again.
Dave