Often the application windows aren't wide enough in order to display all 
the buttons on the toolbar. Yes, there's a simple solution for that, just 
resizing the window.
But I think you should implement something like this (screencap), 
scrollbuttons that scrolls the toolbar only, not the whole window.
But they should be very discrete, and of course they will only show when 
needed.
Anyway, who arent't the windows wide enough by default? Often its just a 
matter of some 20 pixels or so.