Are you sure they're not "teasing" you when they say you cheat? Do you have any siblings, cusack? My brothers and I use to give one another a hard time, just because we were kids "together". There's a certain amount of "Ah, darn! You must have cheated!" natural feelings in a team, etc. If you haven't played with a group before or are an only child that might seem strange to you and/or if you have been "protesting" your innocence, that might make them want to give you a hard time.
The type of people playing on such large, free, public sites are going to be scum I think. It's like a sleazy "bar" atomosphere, they're just killing time, not really caring about playing the game. I have only played once and that was checkers! And I had a horrible experience so didn't bother anymore. Have you tried Pogo or any other sites? There might be some less crass ones?
http://www.pogo.com/marketing/landin...1_A0500_LP0500