Updates to Counter-Strike: Source have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Counter-Strike: Source
Fixed new weapon firing integration causing some guns to over-fire on single taps
Fixed a couple of cases where machine guns could skip slightly with enough lag
Fixed c4 explosion pre-caching
Added precise audio timing fixes for client-side prediction
Increased the tolerance for skip detection in client side audio to prevent sound dropping out due to client clock drift
Completed work on clan tag strings validation
Get the full article at store.steampowered.com