Voyager Glitch?

Hello all, first let me introduce myself, I’m David, I know a little about HTML and have written websites before. However, I’m totally new to Rapidweaver and I’m slowly finding my way around.
I’m also a photographer and I am currently putting a new website together for myself. I chose the Voyager theme as it seemed to suit my needs. However, whilst I have got the main pages done and I am happy with how the look when I added the gallery page and then added the individual pages i.e. landscape, travel, exhibition, etc it seems to go wrong. The initial pages still work fine but if you click on one of the thumbnails to view the image, the page which comes up has no formatting. The image is left-hand justified and there’s no formatting to the text which is also left-hand justified and I can’t for the life of me seem to correct it. I have deleted the pages and replaced them 2-3 times now and whilst they are fine as individual pages as soon as I select them and drop them on the Gallery/Portfolio page they go back to being unformatted. If anyone has any idea what is going on or what I have done to cause this I would be happy to hear them.