Pretty easy gun to work on. CAF mentioned above will have all the info you need.
It is likely the teeth on the .22 cylinder are worn of maybe the lever/index finger, that is what fixes the same symptoms in the Crosman 38 which is kind of similar design, both parts would be super cheap. Can be ordred from Gravel Agency or Scopes and Ammo, S&A has a $25 minimum order but are very helpful with any questions. Gravel, I am not sure if they have a minimum, but they can't answer many questions from what I understand. (there are othe sources, but these are closest to you shipping wise)
You can fix it yourself, all you need is a screw driver and some patience. Just be careful when opening it, springs go BOING. Some suggest opening it is a bag. I find just doing gently and slowly works, but I have disassembled many guns. Go to the Crosman website, at the bottom they have a section where you can download the schematic, it will show you where eerything goes. Any questions head to CAF, lots of guys just waiting to help.