Missing images in epub

I have constructed a document in Pages that consists of an introduction and then 28 pages of images (either one or two per page) - total document length is 30 pages.

However when exporting to an epub format only the first 22 pages of images show up in th epub although interestingly the final page which is just "The end" doe show up, so effectively pages 23-29 are missing.

All the pages are definately there when viewed as a Pages document. Have tried reducing file size etc.

Any ideas would be much appreciated.