Random White Lines on a Web Gallery

I hae tried a web gallery for the first time. Images from a 1Ds Mk II.

The processed images have white lines on them. Different images are affected after deleting previous attempt and starting again. Some images have 6 or more lines on them a bit like a composition grid and some have a couple of lines or one.

Any ideas?

I can't post the web address because I don't have permision for the images but I might let support know with a case if I have to.

Thanks

Martin