Help! rear projection problem.

Okay, here's the dilemna. I have built a HT room in the basement. My
projector is a Sony 1270Q CRT. I've designed and framed the room to take
advantage of putting the projector behind the screen(about a 9ft
distance for an 84" diagonal). I did this to enhance the feel of a
theater and to eliminate proj. noise. After placing the projector
(directly behind the screen-recommended in the sony manual for rear
application) I am seeing the CRT's through the screen. I have yet to
purcchase the screen material,(I'm sitll in the rough-in stage) I'm
using a bed sheet to set the proj. up.
MY QUESTION..When the screen (probably a da-lite screen) is installed
will the CRT's still be visible? Mirror system is not an option --too
expensive. Help. thanks, Neal