It apparently does not work like normal crumble. So when I die an dlose an item to it, does it put that item in a que to be put back out after the next shift? Cause I lost an item, killed the mob to get make it respawn, but the item was not there...
Clarification on rare crumbles
Part of this new change?
It's "queue", btw, not "que.". There is no English word "que." 
The problem you refer to is one I've heard from others as well... Bug would be my guess.
I imagine this is caused by a lot of rares having a dynamic count (based on the playerbase). If you get the item and there are 10 allowed because we have X playerfiles, then a few days later we've purged/aged off enough old and unused pfiles to lower that number to 9, it's not going to repop when the mob dies again.
That's just my guess, though, as it makes the most sense to me.
I'd have put in something to have a crumbled item not pop back in until after so many hours or a minimum of two world shifts.
But that's just me, eating my eggiwegs, my little droogies. 
Two world shifts...meh...That may seem a bit much perhaps? If we're trying to increase rare circulation...but if it respawns immediately, the person who lost it will likely be there to get it immediately as well...thus not increasing any circulation, and just making it an unnecessary pain in the butt that things crumble...
Two shifts may not be a bad idea. But it would also prove interesting if someone died and both parties wanted that crumbled item...so they'd make a run for it and fight all the way through...hehehe. Would make for some interesting pk situations of groups etc...and probably a LOT of complaints...yeah..complaints..the imms love complaints. 