Bukkit

What steps will reproduce the problem?
1. create a setup like this world1, world1_nether, world2
world1 and world1_nether share it's inventory, world2 has its own inventory
spawnpoint is in world1
2. "/gamerule keepInventory true" in ALL of this worlds
3. put some random things in your inventory and die in every world

What is the expected output? What do you see instead?
what expected: you keep your inventory in all cases
what happened: you lose your inventory, when you respawn in another world
the inventory isn't dropped, its completely deleted

die in world1 - respawn in world1 => you still have your inventory
die in world2 - respawn in world1 => you lose your world2 inventory
die in world1_nether - respawn in world1 => you lose your shared world1 inventory
die in world2 - respawn in world2 => you still have your inventory

What version of the product are you using?
the latest

Do you have an error log of what happened?
no.

Please provide any additional information below.
in all cases you dont lose your EXP as expected