Comment 5 for bug 750139

There are three behavior to be exact which I can reproduce

1. If Guake is in full screen -> press the restore from the top toolbar (between close, minimise, restore)-> Guake will go to a lesser size (X, Y both)-> if you toggle it twice (press F12 twice) -> it will go back to full screen

2. If you try to keep the X axis (horizontal length) less then maximum X value it will automatically go to the full X axis value

3. If the Y (height) is greater then 75% of max (approx) it will go for max X and Y value i.e full screen in next toggle