Help! lightgun+VGA=no joy

Hello all. I have a light gun, and a 20" VGA monitor. I've tested the gun on regular NTSC displays, and it works fine, however when I hook up my VGA monitor, the light gun seems to have some problems shooting straight. It seems to "split" into 2 hits on the screen, to the left and the right of the center. I believe this has something to do with the changing of 15khz to 30khz that the external scandoubler does to the signal, making anything on a VGA monitor concerning games too stubborn to be run on dblntsc possible. Is there a simple fix I can do to the lightgun? perhaps there's a sync signal that needs to be doubled with soldered part from radio shack, or something I could do with the lens on the gun? Any help/ideas would be appreciated, as I don't have any clue on how the hell these light guns work. (info on the specific workings of the light gun would be appreciated, too)

@kvasir

Light guns work because they know where the beam is on the screen at all times, when you pull the trigger it (I'm not too sure on this actually) waits to "see" the beam and can determine exactly where the gun is pointing. Well, I say exactly, but as you'll know they aren't terribly accurate.

The upshot is, they won't work on anything other than a CRT, and I suspect may struggle if the scan-rate is more than 60Hz.

Another reason for problems might be that the software you are using is hard-coded to only work on standard TV-style modes (there will be some logic present to convert from "beam took t ms from origin" to "beam is at x,y", which relies on knowing exactly how long one refresh takes and what the resolution of the screen is)

Chris

@kvasir

Light guns won't work with a scandoubler because the scan-doubler changes the display timing. It also won't work with anything but a CRT (no LCD).

Hans