White line appearing when using Photomerge in CS2

[PJ72]

Hello
I have been trying to merge 4 pictures together using photomerge in Photoshop CS2 and having a problem with a white transparent line that appears on the image after merging.I have tried a big overlap but notice it still appears also I have tried minimal overlap but still the same.Ideally I want to try to keep the overlap to a minimum.
I ve had look here on the forum for similar post but can not find any that match my question.Any help would be appreciated.
Thanks
Paul

 

[Steve]

You can post images here Paul
Post your merged image an explain the problem you're having.
Post the individual images you're trying to merge also so we can figure out a solution.