[Help]Drop a certain type of item(s)

Hey guys...I've been dealing with a problem that weapon drops are way too high and I'm trying to reduce them. As far as I know the id's of the items are like this:

Code:

            Helm = 0x1,
            Necklace = 0x2,
            Armor = 0x3,
            RightHand = 0x4,
            LeftHand = 0x5,
            Ring = 0x6,
            Boots = 0x8

and to check if the item is helm/neck etc you check it with

Code:

ItemIDManipulation.Digit(DI2.Info.ID, 1) == id

I already tried this method and check what items to be added in an arraylist so that 1 of them is dropped but it gives an exception from time to time...even though some items are dropped (and there's no difference in drops...)
Suggestions? :)