Is this a possible runtime bug?

Today in class a student lost the top part of the etoys interface - I
think it's called the Navigator Flap.  So he could not save the
project or interact with the project.
I'm trying to recreate what may have happened

1. Open: Make A Project
2. Right click on the black part at the top.   This brings up halo for
Sugar Navigator Flap
3.  Mouse/grab the icon for rotate, for example.  I get an error
message: Message Not Understood.
4.  At this point, I think this Navigator Flap is gone?  I'm not sure
how to retrieve the navigator flap, when this has happened.

Thanks