This is an fyi post for anyone one who might be have a simular problem. I plan on submitting a problem ticket as well.
I have a project which requires two listboxes (transfer back and forth). The "select from listbox" contains a list of Clients (with each client having a corresponding time zone. One of the requirements is have a dropdown containing time zones just below the "select from listbox". When you select a timezone from the dropdown, the Listbox should select all Clients with matching timezones (so you can easily transfer all clients for that time zone).
Instead of turning on AutoPostBackOnTransfer, I added a button "Sort Lists" that can be clicked if the user feels the need to sort the lists.
Here's where the problem occurs, it seems as though any RadListBoxItem that is moved during the SortItems process looses it's tooltip (if an item isn't moved the tooltip will reamin).
I was able to work around this problem by adding an attribute to the RadListBoxItem (it seems attributes do persist after a sort) and then looping through the ListBox after SortItems and reassigning the Tooltip.
when the sort button is clicked: