This has only started happening since 39.1. If I am downloading anything, close Alt Binz to the tray, come back after awhile and try to open Alt Binz by clicking on the tray icon (left, click, middle click, right click, doesn't matter) It opens up an explorer window to the most recently downloaded items folder. I have to use the task manager to kill Alt Binz and then restart it.
Not sure if it has anything to do with if my screensaver/powersaving is on. If I open Alt Binz right away and minimize it to the tray and immediately open it, it is fine, it only happens after a good 15 - 30 min.