What's wrong with planeshift and shaders set to >= medium?
Athlon64 3800+X2@2,6GHz, 2GB ram, HD3870 (RV670) with R600g, drm-radeon-testing, xorg-server-1.9.4, mesa git, libdrm git, xf86-video-ati git, pageflipping on, colortiling on, swapbufferwaits off, libtxc_dxtn.
Finally planeshift works with S3TC texture compression ON which is great because it's on by default and there is way to disable it within the gui. It works perfectly with everything set to highest expect from shaders which I have to set to 'low'.
I really don't know what the problem is, but I have the same issue. Have you ever figured anything out on this? How about the Intel drivers? Have you tried them yet? I must admit that I am a bit apprehensive to try them myself, but would appreciate any information that can help me figure this out. Thank you.