Currently, the lyrics spec that he's using is not an ID3v2 tag, but the Lyrics3 spec, which is rather akin to the ID3v1 spec, in that it's a big chunk of non-mp3 data appended to the mp3 file.

I don't know exactly what comment field problem you're talking about, so that may not be relevant, but it's definitely not ID3v2, although there's good hope that we can get that to happen in the future.