>Another issue I bumped into was that releasing a child-object, 'inside' the child was also unpredictable. I found that 'setting focus' to, or 'activating' the parent (or container object) and then releasing the 'child' (from it's parent) gave predictable results.
>
>In summary - for timing issues - changing the objects type resolved the problem. For child.release issues, it seems better to have the parent release the child, rather than having the child release itself.

I found that form does have some code to cleanup everything:

IF TYPE("This.RefBizObj") == "O"
	lnObjCount = This.RefBizObj.GetObjectCount()
	FOR lnBizObj = lnObjCount TO 1 STEP -1
		loBizObj = This.RefBizObj.Get(lnBizObj)
		IF TYPE('loBizObj') == 'O' AND NOT ISNULL(loBizObj)
			ThisForm.UnregisterBizObj(loBizObj)
			loBizObj.UnregisterAllChildren()
			loBizObj.oParentBizObj = .NULL.
		ENDIF
	ENDFOR
ENDIF

So the problem appears only when the object is instantiated independently.