I heard that at one time it was a bad idea to have both on a page... is this still true? If it is true, why?
Broco nailed it on the head. Can't work both sides of the fence....one of the other. Isn't there something in the TOS about that too?
you CAN use adbrite with adsense. I did it and nothing wrong happened. You can even put adsense code in Adbrite ad and that adsense ad will be displayed untill Adbrite will have a better ad to show on your site (hope you understand).