First thing to check when the graphics go funny is your cache. How long since you've cleared it? No guarantees of course, but every once in awhile I forget to clear the cache on a timely basis and bad things like you described start happening.
Pawn to queen glitch

kefuffle! I'd like to second what baddogno said! If you are still having trouble, reach out to us here:
https://support.chess.com/customer/portal/emails/new
When I pushed my pawn to the last rank, the option given was a blank drop down with, with only the rook visible. I clicked where the queen would be (at the top) and the figure didn't appear on board however it still was a functional peice, proving so by obtaining checkmate. Here's the screenshot:
http://i.imgur.com/NpevqEe.png