Help me people, i have installed a WinTV card, i have all the drivers and everything working perfectly

Now, i want to play my Sega Megadrive through it, and i seem to remember channel band 39 was correct... I then googled as i was getting no picture, and found it was channel 36 for the megadrive and a few other consoles.
Now, that didn't worj either. So, i let the WinTV program scan, and as the Megadrive ewas the only thing attached when it returned 591.36mhz (Channel 36) i'm led to believe it picked it up fine. However, all i see if a black screen! and i get no sound...
Any help with this?
EDIT: Opened in AmCap, whioch locked onto freq of 590.63mhz and let me play Sonic in bad quality with no sound... But, it at least shows it exists!
---------- Post added at 22:26 ---------- Previous post was at 22:03 ----------
Ok, i forced the overlay mode, which helped

Now i can get an almost acceptable picture on 590.18Mhz (best picture i've got so far)
But, no sound... At All.