Oblio, thanks for that tip. I tried it and it works. I now have a multiline comment field in Tag Panel. The only problem now is that the single-line comment field is still there, but now it only partially works. If I highlight an MP3, I see its comment in both the single line and multi line comment fields.. the only problem is now I have to remember to only use the multi line field, because if I forget and use the single line, after I press save, none of the changes made to the comment are saved. Uggg.
But, at least I have a multi-line field, and it works when I remember to use it! (Hopefully, we can just get a preference in a future upgrade for one or the other, but not both 