The recent patch from 11-04-2013 includes a following changes:
General:
– Fixed problem with changing in-game mouse sensitivity
Single Player
– Fixed the Memory allocation Crash at the beginning of Siberian Strike DLC which was occurring on lower end machines
– Fixed the issue with disappearing HUD after the bullet cameras on Siberian Strike DLC
Multiplayer:
– Improved stability of the leaderboards system
– Improved functionality of matchmaking mechanism
– Fixed the issue with Client not being able to rejoin LAN session
– Fixed scoreboard issue on the LAN Deathmatch
– Fixed stamina. breath and scope’s oscillation malfunction
– Users kicked from the session will not be able to rejoin it
– Server browser will now show all servers from the entire world