New PS2 Slim laser won't travel on rail.

I looked more closely at the issue and found that on the return sensor for the new laser I received there were two metal tabs extending from the bottom. They weren’t very long but long enough to hit the ribbon when traveling out or back to center. I took and filed them down, but had other issues with the laser so I had the seller send another. Sure enough the new unit arrived the next day and didn’t have these two metal contacts. It’s like the new laser was from a completely different batch and just works great (without stopping halfway along the rail).