Strange display with Ubuntu 10.04 on iBook G3 Dual USB
 

There is a strange border around my display after getting Ubuntu 10.04 installed on my 500MHz iBook G3 Dual USB 640MB laptop. There is a partial second display at the bottom of the screen. It seems that the iBook is not recognizing / configuring the display driver. How do I fix this? I know the display driver is by ATI. Where do I find the config files and how should they be modified? Thanks.