Created attachment 96775 [details]
Quick repro case
The attached sample case has a list w/ 3 items and hover attributes on the list items. If a drag on any list item is initiated, that item is removed from the list and a new item is added.
The expected behavior is that none of the items are styled as :hover if the mouse cursor is outside the list, but it is fairly (1:3 chance?) easy to create a state that has a sticky :hover on the drag source. Simply follow the instructions on the test page.
Bug 4117 sounds similar, but the repro actions for that bug are sufficiently different that this might be a separate issue.
This sounds much like bug 4117.