OK, here's the story: When the gun came out I bought it and played with it for a while...then I took it apart with a view to lobbing the guts into a PSX Namco gun I was given. It looked a bit tricky so I put in a cupboard...until now!
I had the urge earlier to do it, so that's what I've been up to for the last few hours. I have had to extend some wires, but I did make 1 possibly major alteration, to use the switch (already in the Namco gun) to reload instead of the two microswitches that are in the Act Labs gun. This involved joining some wires here and there - I thought I had done it OK

I plugged it into my old 333 (didn't have the nerve to plug it into my current PC). It passed the first test, it didn't blow up

The problem is it doesn't seem to 'aim' when I hit the trigger, it just flashes and the cursor seems to 'right click'. Hitting the reload button also does the same, minus the flash.
It has been a long time since I used the unmodifed gun, so I have a couple of questions:
1) What happens when you aim at the desktop and hit the trigger? I think it should flash the screen & move the cursor to where you aimed. It shouldn't 'right click' and bring up the little menu, right?
2) When happens when you hit the reload button (aiming at desktop)? Should it flash (& aim)? It should now bring up the 'right click' menu right?
FWIW I know the sensor is working because when I go to the calibrate screen, I can see a slightly darker 'band' moving around the screen as I move the gun (I don't recall this happening before tho).
It seems as if when I hit the trigger, it is as if I hit the reload button, except that the screen does flash. It could be that I wired something wrong, or just that I have a bad connection...
Thanks for any help guys