Hi and welcome!
I got a passive projection rig myself and i'm sure the problem can be found.
Do you know what kind of polarizers you use for your projectors and glasses? You can't mix circular and linear (actually can by turning/rotating etc, but one thing at the time). The best to use is linear because of less ghosting. Using linear you can't tilt your head without loosing separation. This is not a problem because the brain maintains the best stereopsis by keeping the head straight horisontal aligned anyway.
I'm not sure how to use the stereoconverter you have so leave it for future experiments and connect both projectors to your computer, each projector needs one separate output.
Configure your displaydriver so the projectors works as two independant displays (extend desktop on one of them).
Download the iz3d-driver
. Deactivate any antivirusprograms since some might interfere with during the install. Make sure you choose full install to get all outputoptions.
Open up the iz3d-control center, choose "enabled by hotkey" below directx tab and dual projectors as output. Press apply.
Go to the helptab and push the iz3d-logo (dynamic test). You should see the spinning "something" in both projectors.
With numerical + and - you control stereodepth (separation) and with [shift]+[+] and [shift]+[-] you control the convergence. Play around with it to see what the settings does. For gameplay, start your game and press numerical * to activate stereo. Stereocontrols are the same as for dynamic test.
If the image ghosts you probably have unmatching filters (polarizationangles or mixed polarizers) so tell what kind of glasses you have in this case and if possible even the filterpolarizers.
Mb: Asus P5W DH Deluxe
Cpu: C2D E6600
Gb: Nvidia 7900GT + 8800GTX
3D:100" passive projector polarized setup + 22" IZ3D