Those are the ones that use the IR sensors, right? What's the issue? I never had any luck with getting light guns to work properly, but I was using a different gun setup (can't remember the name offhand, but it used an svideo passthrough to a CRT).
Also, which games have you had an issue with? Remember that games like Operation Wolf and T2 work differently from games like Point Blank and Area 51. I'm pretty sure most of the "static mount" gun games look more like a joystick rather than an optical gun.