Double screen settings not retained. At each restart I have to setup both screens again.

Hi,
I struggled to setup an external monitor at 1920x1080 with a retina macbook pro.
I am on a retina MacBook pro, with Win7 64 as a VM. Parallels desktop 10.0.1.
I finally managed to find the right setup.
I setup the external monitor correctly and everything works fine in fullscreen.
When I shutdown and restart the VM, screens are all messed up. It inverts the external monitor with the MacBook one, and I end up with my retina setup at 1920x1080, the external one at retina resolution, and the external as primary screen. And I have to redo all the setup at each startup.
Any suggestion?
thanks