I bought a new "used" gen 3, 34 that had this same problem. It had very few rounds through it when I got it, it looked new to me. I've got the updated 30274 ejector on order. This morning I was fed up with it, and swapped a Lone Wolf 9mm LCI extractor (spare I received in error on an old order)into it just to see. It cleared the problem up for the rest of my practice, about 250rnds. It ejected up to the right and over my shoulder, but away from me. I wish I'd put that part in sooner!! I'm running a factory recoil spring on a SS guide rod, and was shooting W.W.B. from Wal-Mart. (My Montana Gold order should arrive today, until then I'm out of my preferred loads.)
I don't know if this would fix anyone problem with their pistol, but it seems to have corrected mine. I though I'd throw this out for info to you guys......
Scott.