new iPhone not showing up in iTunes while disconnected

i purchased a new iphone4S the other day, and its not wokring the same way as my ipad3g or original iphone4.

when ios5 came out, i updated both my ipad and iphone4, and after connecting and syncing, i dont remember doing anything special to get them to stay connected wirelessly, but they were both constantly shown in itunes conected or not.

now, i have retired my iphone 4, and its now wiped and removed from itunes. my ipad still shows up, and i can kick off a sync while its not connected.

my new iphone4S will not show up while its not connected, but it will sync only when plugged into power. the iphone4 and ipad would sync whenever i wanted them to, charging or not.

can anyone shed some light on this why i cant get my iphone4S to behave like my other 2?

thanks!