As gfrancisdev describes, you need to right-click the offending item, then move the mouse-pointer to highlight "Delete", *then* press and hold Shift, and click on "Delete" in the menu. It will then pop up a message to ask if you want to delete the item permanently, as this will cause it to bypass the trash bin. Obviously, you can release Shift once you see this.
(The traditional Linux Shift+Del for this action does not work on the Pandora at this time, unfortunately. Hopefully the trash bin will be moved soon.)