Another bug that I just discovered, it has been a while since I seen it, but it's back!
If you have an external USB HDD and a dock with a Recycle Bin docklet, then when you delete something from that external HDD and empty your Bin by right-clicking on that docklet and selecting "Empty...", then on occasions the ObjectDock.exe locks onto your USB HDD and it becomes very difficult to Safely Remove it. My only remedies so far been Unlocker and LockHunter programs that unlock process handles off the HDD. That's very naughty behaviour by OD+, please fix it!
EDIT: added a screenshot of the window below: