InventoryCloseEvent is fired twice in some cases (print it if you don't believe me) and CE's are not clearing inventory after "handling items" in InventoryCloseEvent.
If you need more info on this feel free to contact me.
Thanks for the report. There was already a similar problem with some events firing multiple times under certain conditions. For this particular problem, the fix is fairly easy as you described :)
InventoryCloseEvent is fired twice in some cases (print it if you don't believe me) and CE's are not clearing inventory after "handling items" in InventoryCloseEvent.
If you need more info on this feel free to contact me.