Chopping and recocking issues

Here's the basics:  I am shooting a 98C that I hadn't done any upgrades to other than a J&J ceramic barrel.  Last year I had not one problem with this gun, other than some issues with a valve that went bad, but I replaced it and we were fine.  This spring, just a couple weeks ago I tore my gun down, replaced o-rings, and put in a different valve that Tippmann had sent me, since on my 2nd valve the screw holes had been stripped.   Oiled it up, made sure the ball latch was good, and went to play.  Well, I immediately started to chop balls, and this was the same brand and type of paint I had used the year before, so I know the bore match and paint was good to go (I shoot the WGP Perfection and Domination).  Then, as I was shooting fast, my gun would just uncock, and I would have to recock it to get it to shoot again.  This only happened when I shot fast, not all the time.  So I thought, welp, maybe I am just outshooting my hopper, so I put a cyclone hopper and an expansion chamber on my marker.  Went to play again this last week, and same thing.  I was chopping balls whether or not I was shooting fast, or slow, even with the new cyclone feeding faster.  Like I said, I didn't have this problem last year, and it has occured before and after the mods I just put on. 

So what do you think it may be that is causing this problem?  I replaced my detent as well because I figured I might as well start somewhere with replacing things that could be bad, and yes, it is in the marker correctly, and still chopping.  I get paint from one end of the barrel to the other, and just a little in the lip of the actual marker.  It doesn't blow paint all over my internals, or even my bolt for that matter save for when I continue shooting and it does it again.  So I am wondering if I need a new bolt, or if my barrel has somehow gone bad, or what in the world the problem could be.  Any help would be fantastic.  Thanks!

yeah check with a chrono.  Check your front bolt and sand down any plastic that's sticking up.  Check all the o-rings, they could be the reason it uncocks.  Put a different barrel or your stock barrel on and see if you still have the problem.  There may be a little burr on the J&J that's tearing the paintballs.  It sounds like all barrel breaks, so it's MOST LIKELY to do with your barrel, your FPS, or the paint.  You may have a bad batch.

You weren't using the same BATCH of paint from last year, right?