"Fade unselected layers" won't turn off

[Hoptoad]

"Fade unselected layers" isn't working for me right now. Sometimes it works, sometimes it doesn't. Usually it stays on, even when unchecked.

One time, it worked opposite-wise; that is, I had to select "Fade unselected layers" to un-fade all the layers. And one time all the layers un-faded like they were supposed to, but all the unselected layers displayed as shades of gray, not their proper colors.

I'm not doing anything fancy with ASP right now, just basic stuff: vector layers, color styles and imported images.

FYI, I am using a Mac, OS 10.11.

[Hoptoad]

I unchecked "GPU acceleration" and everything seems fine now.

I wish I could use "GPU acceleration" though, because I'd like ASP to run as fast as possible.