A rather small update was just released for both Left 4 Dead and Left 4 Dead 2.
The update should automatically download through Steam.
Left 4 Dead
* Fixed an issue where servers wouldn't relist after the master server was bounced
Left 4 Dead 2
* Fixed a Linux dedicated server crash
* Fixed an issue where servers wouldn't relist after the master server was bounced
Left 4 Dead 2
* Fixed a Linux dedicated server crash
The update should automatically download through Steam.