10.1 simulator won't start in Z10 mode

I can only start the 10.1 simulator in safe mode, by choosing option 4 at startup... choosing option 2 for BlackBerry 10 All Touch (1280 x 768) still starts the Q10 (720 x 720) simulator.

I'm using Bootcamped Windows 7 on Retina Mac Book Pro and my graphics drivers are up to date.

I'm seeing this behaviour with 10.1.0.1483 and 10.1.0.4537?

Anyone else run into this?