STK slows down when AI carts are on the screen

[Tron87]

Hi,
I am running the game in Ubuntu 10.4 on Samsung N210 (1,66 Ghz Atom, 1 gb memory). Surprisingly, the game runs smooth and fast, but only if there are no competitors' karts in front of me. The more of them are on the screen, the slower it gets. Its not just fps, because the whole game starts to look like one big, jerky slow-mo.
Is there any way to configure graphics (level of detail, texture size etc.) in STK to make it quicker? All I found in the menu was the resolution, but it does not affect the problem. The matter is clearly in the other karts, because when I tried to race alone, everything was fine.

[stked]

Are you using 0.6 or 0.7?