It's not a difficult replacement to do yourself, I put the dual ring pistons in my 03 REV and they worked out perfect.
the shop where its at called and said comp. is good,,,bad gauge....did find that the heat shield hook up was wrong and was draining the battery,changing that and battery.
This happened to me this weekend on my 500 SS Trail. I had just changed the plugs and was putting it in the garage before I headed home. when i tried to backup, it stalled. First time it ever happened. Same as you, no beeps, just stalls then starts right up. I did notice over the weekend that my sled was idleing low (about 1000), but after warming or a couple of taps on the throttle, it was above 1500. Then popped into reverse no problem. Make sure the idle isn't too low.
In this world we're living in, we have our share of sorrow . . . answer now is don't give in, aim for a new tomorrow.
Both of my 800's do it. Give it just alittle gas before hitting reverse button. Both of my polaris 340's do the samething.