Shooting stars...MF to Infinity or just shy of it?

I have read when shooting stars, to set MF to infinity and I have also read where you back up one step from infinity. Which is best, especially with the G11?

I guess I could try both, but I was hoping someone could explain which is best and the reasons why.

My understanding is that autofocus lenses go beyond infinity to provide an element of 'bounce' as the lens hunts for focus on distant objects. You can see that extra tolerance at the ∞ end of the scale in the distance window of a DSLR lens. So I back off a tad when photographing the moon. It seems to work, but I am open to correction.

I set all my lenses, inlcuding MF lenses to infinity and back off a touch. From experience, all my lenses will be badly OOF if set at infinity on anything that would be considered inifinity.

Stepping back one from infinity works for me as well but then, what is the infinity setting for? Especially on a P&S like the G11?