Updates to Team Fortress 2, Counter-Strike: Source and Day of Defeat: Source have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Engine

• Increased the resilience of client/server data table mismatches when playing back demos. This will make most old demo files playable again, but with potential visual side effects
  

Team Fortress 2

• Updated CP_Coldfront
  
  • Added map to the default mapcycle and motd files.
    
  • Fixed a server crash issue related to increased maxplayer servers.
    
  • Fixed a couple Engineer building exploits.
    
• Updated the localization files.
  
• Improved the performance of the critboost particle effect.
  
• Fixed a server crash related to carrying buildings at round start.
  
• Fixed players picking up buildings before a round has started.
  
• Fixed an exploit where Engineers could create level 3 mini-sentries.