Mikenas,

 

the problem you are reporting sounds very similar to what some of my users are experiencing. Some buttons are half-way off the screen. What makes this situation difficult to investigate is that no all my users are experiencing it. For some people the editor is maximized as expected but for other people the buttons at the bottom of the editor are almost completely off the screen (I posted a screenshot in my post, it would be interresting to know if your situation is similar).