Sorry to tell ya that you are essentially SOL with that card. I have it and eventually on the GATOS site somewhere I got the lovely clue in on that. Essdentially ATI is a bunch of assholes. Unlikle nVIDIA, they are flat out unwilling to do more than necessary, ya know to woo the hardworking customer in. It took God knows how long to get them to make Radeon drivers, and I dont think that their TV cards are going to be officially supported except tor the Radeon AIW variety. Basically they are refusing any support, even in reverse engineering (not suprised though, I prolly wouldnt do that either)
Now dont feel bad. You should laugh at me. I bought a VE because I thought ATI was well supported under Linux, including the TV Wodnder VE. Nope. OLD cards and some neweer ones work flawlessly and with the full feature set. I never did look at a website and saw a "It works fine", or even at all.
I believe that everyother Brooktree based card on the market will work, even BT878 (I think thats the chipset....) is supported in the OSS software, just that ATI has another singnal co-processor that is totally fucking up all of the efforts of the drivers.
I believe that Hauppage makes the best supported for Linux TV cards
EDIT::: Here is a URL of Gatos -- http://gatos.sourceforge.net/supported_cards.php