I've seen several people shooting P22s at my club. Or, rather, trying to. They always had lots of problems with the gun. Plenty of good .22 semi-autos around, for example Ruger Mk II or III.
I have shot a few thousand rounds thru mine - and purposefully did not clean it for about 700 rounds at one point - and it kept working fine - up until the point where there was so much sludge in the action that it would not cycle any more, and even that got better when the gun warmed up (it had been in the trunk of my car all day in 20 degree weather).
The early ones had some issues the way I understand it. And the brand new ones need some breaking in. I have found that copper coated works best too - the lead bullets tend to gum it up faster.
Maybe I just got a good one.