Video chat completely not functioning
About 3 months ago I downloaded the Messages beta onto my mac. Until this point I had never encountered any problems with iChat on my laptop. Starting a few days after this download, I started running into to multiple problems with video chat's in Messages. These problems included not showing up in my friends buddy lists, and not having audio in video chats that I initiated. I learned about the imagent process and that stopping it in activity monitor might be a temporary fix. I used this for awhile but in the end I decided to just uninstall the beta hoping my problems would be cured and they were...until I downloaded Mountain Lion about a week again. Since this download I've started encountering more and more problems as the days go by. For the first few days everything worked perfectly, then I started noticing the when I started video chats in messages, I couldn't hear my buddies. A few days later I realized that multiperson video chats were completley not working, with the "an unknown error occured" message popping up. Soon my problems got even worse. When being invited into a video chat, I would click accept but nothing would happen and the video preview would stay on the screen. And just today my problems got even worse. When being invited to a video chat, the green light would pop up, but no video preview or message to accept/decline.
Please, please, please help. I've red through many articles and tried everything but nothings been working and its only getting worse.
MacBook Pro, OS X Mountain Lion