Drag and Drop Sortable Tabs only works once

Drag and Drop Sortable Tabs only works once

Hi,
I'm trying to set up two sets of sortable tabs where the tabs can be dragged and dropped between the sets. The tab <li> is draggable, the tab container <ul> is droppable and sortable.
I have it so that it works for each tab when dragging to the other set, and the tab is still sortable, but when I try and drag back, the drop area won't accept the tab. The methods within the drop callback within droppable still progress though.

I have set up a jsfiddle using jquery 1.9 and UI 1.9.2:  http://jsfiddle.net/paulbarrett/ET4xq/19/
Try dragging any tab over to the other tab set, then back again.

What am I doing wrong? Any help welcome.

[EDIT] This has been recognised as a bug  http://bugs.jqueryui.com/ticket/8980

Cheers
Paul