Just curious, do you have an inline fuel filter? If not I'd really consider investing in one, they should cost less than $10 and have the potiental to save you money on car insurance... er... I mean, carb cleaning (stupid Geico commercials).
If the carbs -are- dirty again and you just had them cleaned, I'd be interested in finding out why. Is it just that they did a piss-poor job cleaning, or is it new dirt? If so, whats the condition of the inside of the gas tank? Rust in there?