my ipod is unlock but its showing it lock stil !!

If none of the 5 R's are able to resolve the issue, it's likely a hardware issue, meaning you'll need to have the iPod serviced/replaced either by Apple or a third party service.

http://www.apple.com/support/ipod/five_rs/nano2gen/

B-rock

What warning? It doesn't matter, return it to Apple or a third party service for repair or replacement.

B-rock