Hi smokindeuce,
The button isn't sticking but I applied some lubricant anyway and that helped a bit, however the button is still a bit hard to push down (as in the spring itself is too strong). The way I hold the PV puts strain on the fingers when pushing the button.
I repositioned that small white plastic bit further down the spring and that helped relieve the force needed to push the button in.
It's not too bad now but if it's possible to lower the force even further, that would be great. But the problem is that if I move the white bit down any further, the spring will touch the battery, which I'm guessing will activate the unit indefinitely.
Perhaps shortening the spring is the solution?