Cant see Selection Squares - Bootcamp IMAC - windows 7

Hi guys,
I LOVE this game but i am having issues with my game.
I have checked the Unit Squares on in the UI settings but when I select a unit it doesn't show up.
Its very frustrating, I can never find which unit(s) I have selected.

My machine information below:

Apple IMAC12
Bootcamp - Windows 7-64
System Model iMac12,1
System Type x64-based PC
Processor Intel(R) Core(TM) i5-2500S CPU @ 2.70GHz, 2701 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date Apple Inc. IM121.88Z.0047.B1F.1201241648, 1/24/2012
Installed Physical Memory (RAM) 4.00 GB

Graphics.
AMD Radeon HD 6700M Series
Adapter RAM 512.00 MB (536,870,912 bytes)
Resolution 1920 x 1080 x 60 hertz

Any help would be really appreciated.

Thanks!

First make sure that you actually running game on discrete video card. I'm don't sure if there any specifics on Apple hardware, but for normal laptops I give this link:


Then check if you use most recent drivers for AMD video card from AMD website:
http://support.amd.com/en-us/download/mobile?os=Windows 7 - 64

Why are you playing PA through bootcamp?

PA works natively on Mac.