I was on the verge of submitting 池哲太郎, but I couldn't find anything 100% solid. I could only find the name romanized without the kanji alongside, as if it was written that way in a booklet, here:
http://mimizun.com/log/2ch/morningcoffee/1087914454/ (search for "Bass: TETSUTARO IKE"). However, Yasuo Asai, who also worked on the album that I got the name from (
http://vgmdb.net/album/8932) also performed on the "W" album, so it's definitely possible.
My googlin' skills probably aren't the best either, so maybe someone else can find something.