Yeah, the same thing happened to me the first time I took mine out.
I put the spring back on and then it happened again.
I then popped the axis pin out and removed the BHO.
Went back to shooting and then the axis pin I had removed and the one holding the FCG came loose.
Then I got so pissed I tore the whole thing apart
Worst part is I was on a weekend shooting trip..... Oh well, lesson learned!
The day after I got home I shipped my internals off to Pauly for polishing and profiling.....
For anyone thinking about having it done,,,, I highly recommend it... He does excellent