aim and ichat

i have a macbook air, osx operating system version 10.7.3 and i've had it for a few months. recently my ichat stopped letting me vc, sceen share, or audio chat (i use my aim account on ichat). i have aim version 1.0.9. and i dont remember if i installed it myself or if it came on the computer. i tried going to the apple store and they said it was a problem with my aim and i dont know what to do...any suggestions?