Really? Sorry to hear that. It's working fine on both my Mac's here, with and without hardware acceleration. Perhaps if you comment out each of the DrawRect operations and then add them back in one by one you can tell which part might not be working right? Let us know what you find out.
You could also try changing each DrawRect to only draw size 400,600, then you should see the first part of it working in one half of the screen to compare.
You could also try changing each DrawRect to only draw size 400,600, then you should see the first part of it working in one half of the screen to compare.