This happened to me, I got a replacement phone from Apple, and when I did the restore from iCloud, only one backup from November was showing, but when I setup the phone as a new phone with my Apple ID and then went to the iCloud storage, it showed three backups. So I did some research online and someone posted that they had that same problem, and it was because the backups done on the old phone were from iOS 5.1, and the new phone still had iOS 5.0. So, I setup my phone as a new phone with my Apple ID, went to the update software, updated to iOS 5.1, and then did the reset (erase all settings one), and when I did the restore from iCloud option in the beginning, ALL my backups were there!!! Maybe this is your problem. Hope that helped.