1.
If you manually stretch the window to fit the screen like this:
when you maximize the window, it shrinks horizontally like this:
But if, before maximizing, you shrink the window vertically or horizontally:
the resulting maximized window fills the whole screen space just fine:
2.
When the window is maximized, title "Mediamonkey" gets transparent and you can see your desktop background through it:
3.
This bug may happen randomly, but the following example triggers it every time.
If you start Mediamonkey not maximized and then click on the Windows taskbar and then move your cursor over Mediamonkey, you get something like this:
), but...