I just switched back to 21.2 (from 21.1) after not using it for a while,
and noticed the change in the menu structure, ie the movement of the frame
and window commands from the File menu to the new View menu. I don't mind
this in and of itself (in fact, it makes sense), but it runs into trouble
with some modes. For example, if you switch to html-mode, the View menu
is replaced by html-mode's View menu. No more "New Frame" or "Split
Window" via the mouse.
What this really boils down to is poorly behaved packages that assume that
there's no standard menu named "foo" and don't bother checking. I
don't
know that there's an easy solution to this.
-Jim Potts