Please describe the problem:
Adding an item to the queue does not allow to add an item to the queue two times.


Steps to reproduce:
1. Add an item to the queue.
2. Add the same item to the queue again.



Actual results:
The item is not added to the queue, because it is already in the queue.

Expected results:
The item is added to the queue one more time.

Does this happen every time?
Yes.

Other information:
Even if it is not "common" usage to be able to include file multiple times to the queue, it should be possible. Perhaps enabling this feature by an gconf-entry or an option in the preferences.

Thanks!