The ExplorerManager is not visual component and as
such it can be changed from any thread, that is
fine, but I have noticed that views displaying the
content of the manager (for example ListView) in
its listener attached to the ExplorerManager
immediatelly calls to Swing components methods.
That should be fixed by transfering the update
methods to AWT thread.

I have observed it while using Tim's
workspaceswitcher/outlinesrc viewer that listens
on position of cursor in editor and changes the
selected node for its listview component. Because
the change is done in RequestProcessor and
together while repainting content of editor, it
causes swing hard times and it often paints
complete nonsences.