what is this discoloration looks like missing scales?

Had this guy since he 9/15/12 always thought it was just from shedding or something. but he's always had it anyone know what causes it. tried to take best pics I can he doesn't like to stay still.

http://imageshack.com/scaled/800x600/10/9b4n.jpgUploaded with ImageShack.com

http://imageshack.com/scaled/800x600/12/r4yq.jpgUploaded with ImageShack.com

http://imageshack.com/scaled/800x600/826/f17a.jpgUploaded with ImageShack.com

Looks like he lost a few scales at some point. They will probably come back with time, but if they don't it really shouldn't be anything to worry about.

I've seen that before on snakes that have had a dry shed but it usually goes away after the next good shed. Odd that it's been that way for over a year...:confusd: