Don't know if this is the right place for this but I have been scouring the forums for reported areas of the screen that have green / magenta hues only when viewing through the 3D glasses (glasses don't even have to be powered up).
On the thread by Ron Jones, he talked about polarization retention by the screen material and I saw some images from owners there that had a screen that looked just like mine.
This isn't my projector but mine looked just like this.

After many hours trying to get information from Stewart Filmscreen (I have an old microperf Ultramatte 150 - circa 1997) I finally got a local dealer to bring our several screen samples (including the Studiotek 130 G3 - which has been reported to eliminate most of the color hue issues).
After all that, none of the materials eliminated the problem. It was there with the 3D glasses that came with the projector, a pair of glasses that came with a play station 3D monitor and a pair of glasses from Monster.
I was about to plunk down almost 5K for a new screen when, out of frustration, I call esupport at Sony and the support person sent me a 'lens cap' with a rectangular window in it and some material that looked like it had a coating on it.
IT WORKED. The 3D images are free of 99.99% of any color hue shifting and I saved $5K. The lens cap was free (though I shouldn't call it a lens cap). Sony didn't say what they called it and it came in a small mailer wrapped in bubble wrap with multilingual instructions for 'Mounting the Lens Filter". It is clear and does not alter the light output not does it affect 2D images.
Just thought I would pass this along in case someone was about to spend mega bucks on a new screen.
Edited by blinco_wa - 7/18/12 at 11:00pm