Without seeing the images it would be difficult to tell. However, I usually find it best to overlap images by 25% to 33%. That gives Photoshop plenty of data to use to align the images.
I believe that was the problem I need to overlap the images by at least 25% and I did not do that.
Steven C. Vannoy
205 East 1st Avenue
Roselle, NJ 07203
908-241-1117 ext 5211