Nikon AF NIKKOR 50mm f/1.8D Lens

When I took my new 50mm 1.8 out of the box, I was surprised that it was made in China. First, I thought that Nikon quality assurance would resolve any issues. When I was mounting the lens, I noticed though that the fitting is very tied compared to the other lenses that I have. All the other lenses have this smooth slip in and out action, while the new 50mm 1.8 made in China is grinding through the ring.

As to the quality of optics, I can't really judge that. I did notice an improvement in sharpness over one of my F3.5 zoom lenses. Whether or not it is the level of improvement that should be expected I couldn't tell. Given the strange tightness of the mount however, I am somewhat concerned if I am not losing anything from the picture quality as well.

I posted this question to Nikon and I will update this note when I get a response. I also asked if there is a version of this lens that is made in Japan.