My Nikon 35mm 1.8 is acting weird. How can I tell if it needs to be sent back to Nikon for repair. I think it's still under warranty as I got it 2 years ago. Problems: When I am mounting it on D90, it is very tight and also tight when taking off. Only lens that feels like this, and I just noticed it maybe 2-3 months ago. When its trying to focus, I almost feel that it's making a noise that is louder than usuall. I don't have a camera store around here, would it be a good idea to call Nikon or take it to a store (an hour away) for evaluation. Thank you all in advance!