tv capture

i have an ATI all in wonder radeon using TV capture. i am using the ati multimedia centre 7.6 (and previously 7.1) to capture. when i go to define the compression/codec settings, the "configure" button is grayed out so i can't configure compression settings for whatever codec i'm using.

i have contacted ATI, but do you know of any good free capture programs that would let me catpure in xvid or dvix? thanks!