If you are seeing pictures where the bottom half is gray, its likely that your connection between MediaTransfer on the iPad or iPhone is being disconnected from the server.
Turn passive mode off in settings.
Make sure you are on the same wireless network as your computer.
A few users see this problem consistently when using active transfers. We have confirmed that this is an Apple bug in iOS and are working with them to get it fixed. We apologize if this is happening to you.