I just upgraded to 10.04 on my Dell optiplex GX280 and now OpenGL isn't working (xbmc and cairo dock won't start).

Here are the (i think) relevant lines from lspci:

00:02.0 VGA compatible controller: Intel Corporation 82915G/GV/910GL Integrated Graphics Controller (rev 04)
00:02.1 Display controller: Intel Corporation 82915G Integrated Graphics Controller (rev 04)

What should I do?