Collection Adding Everything Twice - Design Time

I have implemented a simple collection of objects using IList and put the
following attributes on the collection property.

[Category("Behavior")
,Browsable(true)
,DesignerSerializationVisibility(DesignerSerializationVisibility.Content)
,EditorAttribute(typeof(CollectionEditor),typeof(UITypeEditor))]

Everything compiles fine but if I add objects at design time it trys to add
all the objects multiple times.
For example:
I add OBJ1 - this works fine.
When I add OBJ2 - it first adds OBJ1 and then adds OBJ2
When I add OBJ3 - first it adds OBJ1 then OBJ2 the OBJ3.

It doesn't serialize like this but it causes the display to do this. Has
anyone else ever ran into this. It happens to me on all my collections. I
am sure I am doing something wrong I just don't know what. If you would
like a copy of the source let me know. It is too much to post in this
message.

Any help is appreciated.
-Adam dR.