I thought Greg had done XORing to make the grid show up, but maybe not.
I did, so this is kind of surprising. First I've heard of this, and I thought we had some other Mac testers verify it.
edit: Looks like there is code that specifically checks if it's OSX and doesn't do the XOR mode. I don't remember adding this in so we'll have to find out who did (Jon?). Maybe it was to prevent another issue.
edit 2: Looks like it was causing the scrolling/rendering to happen very slowly in the Scene Designer for Mac users. Here's the comment: "Turns out this is a bug only on Mac in the Java runtime. I'm gonna turn off XOR drawing for Mac users."