MMF2 fullscreen different Than MMF2 Dev Fullscreen?

So in MMF2 Standard, when my applicatiuon is running Fullscreen, it's completely proportional. I have an 800x600 screen and it appears that MMF2 "zooms" and displays the 800x600 frame proportionally. Anyways in MMF2 standard when i go fullscreen my frame takes up the whole screen and there is no distortion. PERFECT! :)

-But-

I just upgraded to MMF2 Dev and when I open my game in MMF2 Dev, the full screen doesn't ZOOM in on my game, but just stretches the window, not the actual frame. I dont know if there is something different about MMF2 Dev, because i checked all the exact same boxes that I had with MMf2... This is really a problem for me considering I was just going to release my game this week when this happened. :(
Please Help Me!

Figured it out! The "Keep Screen Ratio" button is the opposite in MMF2 Dev and Fusion 2.5 Dev. Thanks anyways to all who answered my original post! Oh wait, no one replied to my original post! Whoops, my bad.

>> Figured it out! The "Keep Screen Ratio" button is the opposite in MMF2 Dev and Fusion 2.5 Dev.

O_o There is no difference at all between Standard and Dev. Unless you used a very old version of 2.0?

EDIT: could you send me a MMF 2.0 MFA app where I can see the difference please?