Valve has announced that they have fixed the Achievement bugs in Left 4 Dead that were a result of The Sacrifice campaign [hint=Downloadable Content]DLC[/hint] being released. They also stated that in most cases, any progress lost through this bug would be restored and merged with any progress made since this bug came into play.
Valve have also made the following changes to Left 4 Dead...
- 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.
- Fixed the Sacrifizzle achievement.
Source - l4d.com/blog/post.php?id=4888...