There is a fix for this.
Start steam, and directly launch the game. Now, click on "find servers" and select the favorites tab and in the filters options, select from the dropdown menu "Secure", even if it's allready there. Exit the game. Start the game up again and open the server browser at the favorites tab and select "Secure" again and click "Refresh."
Don't do anything else in between like browsing for server with the out of game server browser.
M_A_C
Another one is to go into the steam dir,find the servers folder and delete the serverbrowser.dll file, it will come back{but i usually just move it out of the folder just in case}