Magic Find not working?
As far as I know, ANet hasn’t released any actual numbers for magic find. However, considering how almost every other % increase in the game works, having loads of MF may not really help a huge amount.
If you figure that you have, for example, a base 1% chance of getting a rare item to drop (assuming you win the roll for loot at all from a mob), your 173% MF would only give you a 2.73% chance of having the same item drop.