I have a similar issue. I installed Natty a couple of days ago. When Unity came up, it was sluggish and many apps crashed. I switched to "classic with no effects", and continued setting up stuff. Later I realised that hardware acceleration was not working. I fixed it (don't remember how), and the problems became worse.
Since my idea for this machine is to use it as a media center, I installed many of this apps, and thought that there were buggy, as I could only see blank screens. Later I realised that not even glxgears works. If I disable KMS, or set LIBGL_ALWAYS_SOFTWARE=1, they work, but so slow that the apps are unusable. I have already tried installing the propietary drivers, which tell me that my card is unsupported. I installed the X edgers drivers, with no improvement. Tried different xorg.conf tweaks that I found on the 'net, no dice. As most of these media apps for some reason require 3d accel (stupid shiny effects), I need to make this work. $ lspci |grep VGA 01:05.0 VGA compatible controller: ATI Technologies Inc RS690M [Radeon X1200 Series] $ glxinfo |grep render direct rendering: Yes OpenGL renderer string: Gallium 0.4 on ATI RS690 GL_NV_blend_square, GL_NV_conditional_render, GL_NV_light_max_exponent, -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in Ubuntu. https://bugs.launchpad.net/bugs/755791 Title: [RS690M] No 3d acceleration in Radeon X1200 with new Gallium r300 / 3d drivers in 11.04 Beta 2 _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp