Light Gun problems with House of the Dead 2

[cods]

No joy, unfortunately.
Even after adjusting the TV every way I know (TV is Loewe Ergo 70cm), gun calibration does not work any better at all. Even if I can calibrate the first time on each of the 3 shots, the gun cursor jumps around inaccurately, and says it is pointing off the screen around 40-50% of the time.
This seems like some sort of PAL/NTSC problem, but like I said in the first post, I've got the problem with both versions!
Any other suggestions are welcome!
Rgds.