Last night a few updates were applied to the Xbox 360 version of Left 4 Dead.
Foremost is the ability to recover achievement progress that was lost after The Sacrifice release. Recovered progress will be added to any new progress made since the release. In a few cases it may not be possible to recover the data for every achievement, but the majority of players should see their progress restored.
The update also includes the following:
• In Versus mode Tanks will spawn in stasis until a human player takes over. Tanks in stasis are invisible and invulnerable, and won't move or attack. • Tank speed is no longer reduced when on fire. • Allow players on the Infected team to manually spawn during finales. • Added a vote option to toggle All-Talk. • Special Infected that causes a Survivor to stumble into a "ledge hang" situation will receive 50 points. • Bullets that first pass through an infected character before striking a Survivor are now ignored as friendly fire.< • In Versus mode car alarms will now trigger anytime a Special Infected pulls or stumbles a Survivor into an alarm car. • Survivor Bots no longer try to melee exploding barrels out of their way.