The North American Steam version is bugged...they uploaded the wrong version, the developer version.
Not sure if it's fixed yet, but I'm waiting a bit before purchasing.
http://www.anandtech.com/show/4735/developer-build-of-dead-island-accidentally-released-on-steam
Edit: First day fixes. At least they are fixing issues right away.
- Fixed map synchronization when player joins during map load.
- Fixed saving player re-spawn position when playing in co-op mode.
- Fixed occasional inability to complete sidequests in Laboratory.
- Improved enemy awareness (zombies).
- Fixed occasional bug with NPC's hands bend (IK)
- Fixed spawning enemies in some quests after joining co-op game.
- Fixed showing locations on invisible NPCs.
- Fixed potential path blocker when quest "Knockin' on heaven's door" was completed before talking to Dominik during the "On the air" quest.
- Fixed displaying gather rings near some doors.
- Fixed enemy reaction to fire.
- Fixed enemies' health and stamina bars in co-op.
- Fixed filtering of games in lobby.
- Volume of pickup's engine has been increased.
- Fixed a number of issues causing game instability.
- Fixed the switching of maps upon player death.
- Fixed enemies unable to reach the player on some arenas.
- Thrown items cannot be picked up by co-op players for five minutes.
- Items from freshly opened containers cannot be picked up by other players for five seconds to prevent theft.
- Fixed animation glitch when trading with team members.
- More than one player can use a ladder at the same time.
- Fixed stomping execution animation when target's attacked by a second player.
- Fixed the infinite respawning of shooting enemies.
- Fixed not hiding menu if players die inside a vehicle.
- Fixed item level calculation when playing New Game Plus.
- Added information about players requesting pause in co-op.
- Fixed A.I. animation glitch after fast-traveling or using a map portal.
- Added distinction between quest checkpoints and other types of saves.
- Fixed bug causing all inventory to disappear.
- Fixed reloading and kicking. After the clip goes in, the reload is a success.
- Purna can gain bonus rage from both "Grim Inspiration" and "Inspiring Kick".
- Only "Walker" type enemies increase the extra XP of the "Combo" skill from Xian's Survival skill tree.
- Health regeneration is disabled during grabs.
- Focus on items in shops not changing after selling or buying.
- More HP for NPCs in escort missions.
- Butcher enemies won't spawn at all during escort missions (hooray!)
- Fixed tracking after loading checkpoint.
- Increased minimum vertical distance to count a waypoint as passed for NPCs (they no longer wander back-and-forth).
http://www.destructoid.com/here-s-the-list-of-fixes-in-dead-island-s-day-one-patch--210646.phtml
