[racket] DrRacket slow editing

Installed DrRacket on my Ubuntu 10.04 LTS setup and found that I editing
was really sluggish. It takes several seconds for a key press to become
visible.

I removed the graphics card driver (Nvidia accelerated graphics driver
version 173) and used the default one that came with Ubuntu and DrRacket
works fine. However I cannot enable the desktop visual effects without
the Nvidia driver. 

Is there a setting where DrRacket uses a different graphics driver so
I can keep the visual effects and use DrRacket.