I use the plugin MoneyDrop on my server with OtherDrops as well.
There are some unique mobs I have created with OtherDrops and random events that should be dropping MoneyDrop's money item with the value I specified, however despite watching a chat indicated message that Money has dropped, I see none appear in-game and my balance does not change either.

I have double, triple and rechecked again that it was configured properly and even tried both MONEY_DROP/2 and MONEY_DROP/2-5 or seperating them from one another in their own drop: and quantity: areas...
No luck.

I'm using:
OtherDrops 2.8b.573
CraftBukkit 1.7.9 (no idea build number)
MoneyDrop 2.2.0