Steps to reproduce:
1. Open RText and have two plugins (e.g. Source Browser
and File System Tree) open and docked on the
left-hand-side. Have File System Tree selected.
2. In the Plugins -> Options -> File System Tree panel,
change FST's location to anywhere else, such as "Right."
FST will be moved to the new location, and Source
Browser will be selected in the left-docked tabbed
pane, but it's title bar will still say "File System Tree."