Mouse over an item and ctrl-right click to open the upgrade/shard interface. Sometimes when doing this, the item detail popup of the item you had selected will linger on top of the interface that opens.Expected Results: Opening upgrade/shard interface closes other popups.
This is race condition between showing the Item Detail popup and opening the Upgrade Shard popup. They both show up if the mouse-over and ctrl-click happens at nearly the same time.
Fix: as stated by SupaFly, last pop up to open should close other modal dialogs that are not its parent.
Workaround: don't click so fast; ensure mouse-over popup is open before ctrl-clicking.
*Correction above, opening upgrade/shard interface is Ctrl+Left-click, but you get the idea.
Seems to be some kind of race condition between the mouse-over details and the upgrade/shard interface. So the faster you select and item and left-click it, the easier it is to get this issue.
Reproduction can be increased to 100% by holding Ctrl and moving mouse over an item while spamming left-click.