Stacked balloons won't keep relations

I have an assembly detail view in which I have a ballooned hardware/fastener stack. Some of the items are hidden from view but I linked them to their respective design tree item. My problem is that I can't seem to keep the relation for the stacked items once the file is saved, checked into PDM and checked back out. For instance; they look fine when I check them in but when a "checker" checks the drawing out, they show up as empty (?) balloons. When I try to open it to see what's wrong, they are still empty.

I'm stumped...NEED HELP!

SolidworksDrawings And Detailing