Limit the Haste to 29999, this will make the haste stop at 29k and it won't give you the 0% thing you are talking about.
Altrought i've not been in this position. However i got a similar problem with creatures too, That would be the Factions like Argent Dawn or ratchet, which usually prevents players from attacking other players. If i were to attack a player from the horde while im alliance, then the guards won't do anything, they will get hostile, but they won't move and you nor can attack them, However if i attack that player back and i die, and then i respawn myself by .revive, then they will start attacking me as they should.