I haven't had any success with the gun/monitors/ArcadeVGA card combo yet....
On my W-G7901
If the gun is plugged into the middle vga port (dedicated arcade monitor port) of the ArcadeVGA, then the screen goes white and stays white as soon as the computer is turned on. It looks almost as if the gun is stuck in calibration mode. No luck on this port.
If the gun is plugged into the secondary vga port along with a PC monitor, then the computer boots normally and the BIOS screen is visible on the arcade monitor until Windows loads. As Windows loads, the PC monitor flashes a few times, but once Windows is fully loaded, both monitors go totally blank and cannot be revived.
On my NEC presentation monitor
This commercial presentation monitor is very similar to a D9200 in that it can sync on anything between 15-31KHz with a max resolution of 640 x 480 non-interlaced. As most of you know by now, the ArcadeVGA card will fix the connected "arcade" monitor to 15KHz so a 640 x 480 res is interlaced.
When this monitor is connected to the middle VGA port on the card with Windows loaded, the gun seems not to be recognized. It is installed properly and shows up in the Device Manager, but switching to Calibration mode on the gun does nothing. The white screen doesn't come up and shots (mouse clicks) are not registered.
No luck for me so far with the Act-Labs USB gun and ArcadeVGA...