PLASMA LAG QUESTION

So I am at a buddy's house and he has a new plasma TV that we're trying to get set up with his wii. We're trying to play the new Guitar Hero 6 and there is just absolutely insane lag.

Currently both audio and video latency adjustments are set to 106ms and I still can't play drums because of how far behind it is. If I play by ear I hit no notes, and it's just not possible to play drums visually and separate it from what you're hearing.

So my question is: is there some trick to getting it adjusted right? We've spent way too long futzing it and we kinda just want it to work at this point :\

TIA, gents!