If you dock multiple documents in a tabbed document container, a glyph appears with the tooltip "Active Files".
Underneath is a context menu with the titles of the files.
When the container is resized, so that not all tabs fit inside, then when you click the glyph, an extra menu item appears in this context menu: "Close All But This"
This item does not belong here. I hope this can be fixed.
Note: the menut item appears most of the times, but not allways.
( I have a screenshot, but i'm affraid I can't attach it anywhere )
Aernout van Groen