you could add an action to it which will give a 100% chance of a drop and skip the dropitem rule .... or add a couple 121 actions to give it some variation or only allow it to drop t random
Code:
1000 0 0 801 0 dropitem [itemid]
or try making your chance , and explode chance higher
note:explode chance controls the huge multiple drops that you get from the normal bosses when you kill them with low level pets