Hi,
I found some time to look into this. When the frame was maximized and the tool-bar was disabled, the function x_set_window_size was never called.
The following patch makes the frame exit the fullheight or maximized states when the tool-bar is disabled, which makes the call x_set_window_size reappear. It does NOT, however, return the frame to the fullheight or maximized states when the toolbar is re-enabled (I don't even know if it should). In addition, it does not support frame-inhibit-implied-resize either (which would require a lot more work).
I read in the emacs-devel group that there is a feature-freeze in place -- does this mean that I shouldn't commit this?
Also, the current Emacs master branch doesn't build on OS X 10.6.8 after an attempt to David Reitter to eliminate warnings -- I think it's an easy fix (David don't have access to a 10.6.8 machine but fortunately I do).
-- Anders