Subsequent to posting what was working for me on this link, my TV Guide download also stopped working. Yikes! Tried multiple times on multiple days, same result. The version I was running was 3.6.9 (7513)
As an experiment, I went into my Time Machine, recovered the oldest version of eyetv I had (ver. 3.6.5), launched it, and asked for tv guide to update. It worked!!! Now to see if the working continues.