Currently Being ModeratedMar 28, 2012 7:22 PM (in response to mcarrillo)
Is this in the dock? If so then maybe you moved the "real" iChat app since the dock icon is basically a pointer (alias) to the actual app. If the app moves or is deleted you see a question mark in the dock.
Drag the question mark icon out of the dock. It will go "poof" in a cloud of smoke. Then find the actual ichat app and drag it to back into your dock.
Currently Being ModeratedMar 28, 2012 7:31 PM (in response to mcarrillo)
Also be aware that if you installed Messages Beta, it replaces iChat. If this is the case look for the Messages app. If you want to uninstall it and get iChat back, here are the instructions.
If you didn't install Messages beta, please disregard.