Sorry to hear that. When the menu is showing you should see some squares in the corners which can be used to resize it, and while making it larger this won't visually be updated until you let go.
In the future I can add some options to choose the type of window into a more standard resizable Windows-style one.
In the mean time, you can also set the window size by editing the config.xml file.
Very sorry I can't help more right now, but I'll test and make sure everything's working as it should, and add the extra window options soon!