Return player to previous position on world change (MultiVerse)

The issue I'm having is that when players teleport to another world, it does not save the position they were in, meaning that they get teleported to spawn. Here is an example:

-- This is what it's doing now:
1. Player is in the survival world
2. Player teleports to another world
3. Player teleports back to the suvival world, and is put at spawn.

-- This is what I want to happen:
1. Player is in the survival world
2. Player teleports to another world
3. Player teleports back to the suvival world, and is put at their previous position in this world (where they were when they teleported in step 1)

this actually works as /back command in AdminCMD and my CommandsEX, but only if they did not teleport elsewhere in the meanwhile (/back only remembers the last TP location)

I just created a plugin that does this for anyone who is interested: http://dev.bukkit.org/server-mods/worldpos/

It's still pending approval, hopefully it will approved soon.

does it store more than 1 back position?

No, not exactly.

The plugin just watches for when a player changes worlds, once they do, it saves the position that they were in when they changed worlds/teleported to another world.

Then later on when a player wants to get back to that world, they type /world [world name].

Any teleportation that takes place within the same world will not be saved.