Confirmed with VS 2008 and 2010 - When you have 2 floating panes and you dock them side by side or one on top of the other, "Hiding" one of the panes from the context menu and then selcting "Floating" on the remaining pane will cause this pane to spawn a second identical pane but with a blank caption bar. It seems like when the first pane is hidden the active context menu (the one with the check mark) would change from "Docking" to "Floating" but this is not the case. That is the minor of the 2 issues. Panes should not duplicate like that. The pane with the blank caption bar will disappear after moving it around a bit.