Thanks for your suggestion!

I am selecting random pointers to chase and getting this in almost all of the results:

globals: Environment

declarations: IdentityDictionary

#ActiveWorld -> PasteUpMorph

submorphs: Array

6: PluggableSystemWindow (3168378)

submorphs: Array

3: PluggableTreeMorph (1993854)

scroller: TransformMorph (3408406)

submorphs: Array

3: IndentingListItemMorph (2996756)

complexContents: PointerExplorerWrapper

item: Association

value: Array

... and the last entry in the list is an object that is a subclass of the HWEntity class, like:

22392: HWGround.

Does this mean that my objects are being held onto by user interface objects? My UI elements are no longer being displayed so I don't know how this can be the case.

Thanks again!

Chris