Over the past weekend, Steam users have had problems with authentication servers. The message given by the server was the following:" This Steam account does not own this game. Please login to the correct Steam account."

Steam has managed to fix this error and posted on their forum advices on how to fix this error. Steam users that had this specific problem need to delete a file located in the Steam directory. The embedded file is called "ClientRegistry.blob".
The file needs to be recreated the next time the game is started. For the game to run smoothly, a brief update is necessary.

A few other bugs have been reported by Steam users and the Steam team took them into consideration and worked to fix them. Among the most important bugs signaled by users are: problems with 3rd-party games not launching correctly if other command line has been specified; trouble with "remember password" functionality and problems with full localization pass on all languages.

If I were a Steam fan, I would be sick and tired by now with so many bugs. I wonder why they keep coming back...