Major graphic problem with NiGHTS in SSF

I have this rather annoying graphic problem when running NiGHTS in the SSF emulator. They say a picture is worth a thousand words, so here's a visual example:

http://img13.imageshack.us/img13/8568/nightsl.gif

It happens constantly, making the game unplayable. I tested other 3D games (such as Panzer Dragoon), and they don't have the same problem. I noticed that it happens less often in previous SSF versions (SFF 0.09 beta R2), but it's still there. I also tested on both Vista and XP. SSF presents the graphic error under both OSes .
It seems to be more frequent when there are more applications open using memory, but it's still present when SSF is the only one.

Anyone has any idea about how I can solve it?

Well, I can't really say that I'm finding the same thing. Have you tried setting the "Highest Compatibility" mode under EZ Setting in the Options menu? Also, make sure "Auto Field Skip" is checked under Screen, since that seems to be responsible for throttling the game properly.