i'm assuming iPt = iPhoto... how are you trying to share photos via iPhoto?
Photostream is a great way to share photos that are taken (post iOS5 install) and then sync to all devices that have Photostream on, such as an iPad or the latest ver of iPhoto.
Photostream does NOT:
-stream back dated photos: photos taken prior to iOS5 install.
-stream your ENTIRE album across all your devices: you still need to do a sync via iTunes to get your entire album.