I bought a Tamron from a store that went out of business...lost my receipt ect ect...Finally remembered I had used my credit card for the purchase..got a receipt from them and talked to Tamron in New Jersey...They fixed and returned the camera in less than 5 days to Idaho...and I have had no further problems with Nikon D-300 D-7100 bodies...I have had countless conversations with people over clean this or that...adjusting things on the camera menu...Send it in Send it in...the Generation 2 Tamron has had a few of these glitches