This is simular to another point I wanted to make a while back. on those
combo boxes, you should allow the user to type in the values that they want.
I don't know how the keys are redirected right now (under gtk+), but when the
user clicks on the textbox control within the combo box, the main window
should not capture all the keys.
Some of the combo boxes should limit what's typed to just list items, i.e.,
fonts, while others you want to type your own-style, font size, zoom, ...