I've got an nvidia 7300, under x86_64 linux the shaders make the game unusable.

The top half of the screen is backgrounded with a moire-like pattern, and the whole thing runs extremely slow. Game runs fine without shaders.

In windows on the same machine, shaders work perfect.

I can supply a screenshot later if needed. Any other info would be helpful?

Hmmm... Someone else posted about this not so long ago.

I've no idea if he was using the x64 version though. Have you tried the i386 version to see if it does the same?

OK, screenshot here.
Also note the pixel-wide line at the bottom, it appears to have this pattern as well.

It looks identical in windowed and fullscreen, resolution doesn't matter.

This output shows in the console when I run the game, if this is helpful:

Fluid blood supported (level 4 of 4)
Ambient Occlusion + Bumpmapping supported (level 12 of 12)
Cel-shading supported!
Buffer 0 is dimensions 200 150
Buffer 1 is dimensions 2048 2048

In 32-bit, the shaders work. There is a single pixel row at the top and bottom that seem connected to the reflection on the floor.
Here's a high quality screenshot, you can see what I'm speaking of along the inside top border.

Note the tearing in the middle of the screenshot is due to some wierdness with vsync I sometimes see while capturing screens in linux.

I've been working with fwiffo in IRC, he's on it.