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