I am running the latest version of GameEx and I noticed a problem when I changed my screen rotation. I was running with the screen rotated 90 degrees, but I needed to change that to -90 after flipping my monitor orientation to fix other issues. After I changed the setting, when I go into the game selection for MAME under ANY theme, the wheel images are covered by an "box" that you can see the background through, but you can't see the wheeI image (Logo). I can see them "behind" it, and as I change games I see the logo rotate up or down and out of view, but its clear there is some soft of box blocking the view, like there is an invisible window that is on top of the wheel art.
When I rotate the screen in settings back to 90, it works with no problems. I have tried multiple themes with the exact same results, when you rotate to -90, the wheel logos get covered up.
Seems like a bug since it happens on all themes but I can upload screen shots and files if you need them