Comment 21 for bug 428396

ok, for me (and i'm a regular user, dunno what DRI2 or KMS even means) its like this:
under the preinstalled ubuntu drivers (open source i guess) gnometris is incredible slow, can't even start a game properly.
under the drivers from system->administration->hardware drivers (named: FGLRX) the game is playable and normal speed, but everytime a new piece falls from above, the playing field disappears. you have to move the piece to get it back. if you complete a row and trigger the animation, the field disappears for a very short period, until the animation starts and it gets back.
looks like something has to happen on the field to get it back.
Version: 9.1 (karmic koala) amd64
Graphics Card: radeon hd 4500 series (at least thats what lspci is telling me)

hope i could help