A Steam client update is now available. To apply the update, click the File menu inside of Steam and then select "Check for Steam Client Updates...". The specific changes include:
Steam Client
Fixed a case that could cause stats and achievements to be reset
Show timestamps in both group and individual chats based on global setting
Fixed a Steamworks api crash that was affecting Call of Duty: Modern Warfare 2Tweaked the connection fallback logic to be more robust