Shelter dog behavior

Question
In my search for the perfect dog, the following has happened to me twice, with two different dogs at the same shelter.  The dog will act very sweet and affectionate while in his/her kennel, but when I have the kennel aide take the dog out so I can meet him/her, the dog runs around the veiwing room, and the fenced in viewing area, sniffing like crazy, pretending I am not there.  Is this normal?  Is this simply because the dog very rarely is let out off the leash, or because he is hyper?  If the dog got to know me and became familiar with the surroundings, would it eventually calm down and warm up to me, and be affectionate, loving and playful?

Answer
First i must say i am very happy to hear that your are adopting from a shelter!  Kudos for you :)
The reason the dog is runnig around and sniffing like crazy is beacuse the dog is not let out alot and smells al the different sents around the room!  If the dog is small ebough you should try and hold it, but if it is too big just follow it around and make your best effort to get the dog to notice you.  That quality might mean that the dog wouldn't be the best companion that follows you around all the time, but it will still love you, just not be a dog to follow you everywhere you go.  Most likely when you meet a dog you will know if it is the one meant for you.  Good Luck and if you have anymore questions just write!