This minor bug has been around for some time but I've only just got around to reporting it:

I frequently use the "Edit with Notepad++" context menu command in Windows Explorer. Frequently when NP++ is activated following this command the menu bar fails to show. Also if there are any plugins docked they will not display correctly. Both of these issues can be resolved by restoring down.

I've just tried to reproduce the error after it happened again today and can't, sorry.