As per nilly's suggestion try disabling steam over lay.
1) Click on Steam and click on the "Settings" button. Click on the "In-Game Settings" tab.
2) Uncheck the box next to "Enable Steam Community In-Game" and click OK.
3) Disable the Steam Overlay on specific games only by right-clicking on the game title, click on "Properties" and uncheck "Enable Steam Community In-Game" in the "General" tab. (From steampowered.com)