RainbowImaging Nikon lens to Sony E Mount NEX NEX-3

http://www.amazon.com/gp/product/B003XY4LFU/ref=oh_details_o02_s00_i00

I got this adapter and tried Nikon 50mm f1.8 lens on Nex F3 but I am unable to take the lens off of the adapter. It did come off the camera. but the adapter is sticking with the lens.

No I read description, it says only Nex 3 and 5 (I assumed it would work for Nex F as well)

not sure I  screwed up something while fitting lens on the adapter, I tried to turn clock and anti clock wise, but can't take it out. any help is appreciated