Which message is it? There are several related to video driver updating, and the ones that recommend taking an action all have cancel buttons.
keywc, please re-open if you see a problem.
Same issue, mint 13, I have the latest fglrx from amd's website installed and activated but steam doesn't recognize that fact and gives the "enable prop drivers warning at every startup"
Nothing extracted yet.
Each time I launch steam, I get a message aksing me to install the ubuntu AMD drivers, even if I have already beta drivers installed. I would suggest adding an "ignore" button.