When trying to make a Video or Audio Call from a Gmail account to another Gmail account it throws a window error with the following output: There was an error starting the call
I have the Gmail plugin to talk and checked any Empathy extensions needed for this. The problem happens only on 11.10. in 11.04 it works correctly.
The problem has expanded to Desktop Sharing and Sending files. Both of which do not work either. I think this is all related to a common problem.
UPDATE - Desktop Sharing can be solved by activating vino-preferences
and configuring in the host. After that tell the Empathy host to "Share Desktop". It should work. File Sharing has been solved in one of the updates that came several days ago. The issue still exists for Audio and Video.
UPDATE 2 - Since around June 2012 in 12.04 the option about activating vino-preference to have Desktop Sharing is not working.