MV: Minimize-Maximize-Close bar gone

This is a picture of the top of my screen when I open MV. You may notice that the 3 buttons at the top-right corner are missing.

Is this a glitch, or is there a keyboard command that causes this? No other program I open has this problem.
Here it is in Firefox. Perfectly normal.

 

Sometimes updating your graphics drivers can fix this issue. I had this once before and it fixed itself once I updated.

 

I found a solution. After forcing it to minimize/maximize/restore a whole bunch by right-clicking the image in the taskbar, I got it to go back to normal.

 

I remember that there was a case once where a laptop with two graphic chips (intel for 2D and a dedicated 3D chip) had a similiar effect due to a wrong setting in the intel driver (somewhere in the advanced options, nothing of the regular display settings). If your computer has the similiar hardware you might want to check there if it happens again.