I don't think it is the ammo, but then you didn't say exactly what ammo you are using. Which type is it?
I have fired about 150-400 rounds a week (seriously), every week, for a year (around 10,000 rounds) with mine, and have had very few problems. I clean mine meticulously after every use though, and that helps a lot. These pistols dirty-up something fierce no matter what ammo you use.
What kind of jam are you getting? Nose of the bullet getting stuck on the ramp? Bullet not coming out of the mag? Casing not coming out of the chamber? etc.
The guns work good with high velocity (CCI Mini-mag, CCI Velocitor), hyper-velocity (CCI Stinger), or CCI Standard Velocity. I don't find velocity to be a big issue in cycling the action of these guns. Anything will cycle the action on a P22 no problem. According to the range warden at my range, the Standard Velocity stuff is good for auto pistols because it gets up to pressure qucikly and therefore works the action more reliably. I don't ever remember having a problem with any of the four CCI types I have named though. The few problems I have had problems with have been with cheap ammo (regular lead ammo from Federal, Remington or Winchester).
What is the year code on the gun (AD, AE, etc.). Maybe it has the older mags. If it really is newer production, you shouldn't be having many problems with it. despite their bad rap from their early years on the market, these guns are actually very reliable if you clean them and use quality ammo (preferrable the Mini-mag type). Mine just gets better with age.