You might want to check on your settings also. I have noticed that every wall I have uploaded recently, eventhough I make sure I do not tick the box to only show on my page, the wall is flagged to only show on my page. After I go in and edit that, then they are available in the gallery. Been meaning to write to support and find out what might be causing this.
Whats causing it is the administrators or moderators are putting them on your personal page instead of rejecting them. If your able to edit (uncheck the box) after the fact then its a glitch that you should not be able to do. Nor should you be doing it.