Emacs windows goes "under" the vertical taskbar when maximized

Hi,

When I maximize my Emacs window, it goes under the vertical taskbar -
instead of properly maximized.
That is, if my resolution is 1600x900, with taskbar having 100 pixels on
the right, when I maximize Emacs window, it becomes 1600x900 instead of
1500x900.

Best,
Joon