Transitions not finishing

I have a transition with an onComplete function, I trigger this transition when my assets die in the game, never had issues, today i was testing it on my Galaxy Tab 2 7", and after many “game tests”, suddenly 5 of the transitions didnt finish, the code is this
 

transition.to(hit.sprite, {time = 500, alpha = 0, xScale = 2, yScale = 2, rotation = 45, transition = easing.outExpo, onComplete= function(target)                                          target:removeSelf()                         target = nil                     end                         })  

The problem I had is that the trannsition appeared to be “stuck”, between alpha = 1 and alpha = 0, what happened?? I NEVER pause transitions or anything else, the weird thing is that other 4 similar transitions got stuck, in different times, the first one appeared, then a second later another, and then another… I dont know how to replicate this bug, has anyone ever experienced anything like this???