When we open a page in preview mode (editor.html with preview mode) and click on any link on the page, it'll take you to the page but immediately redirects to previous page.
edit mode works fine and also in publisher works fine.
Select View as Published and then try
I quickly tested the use case on 6.4 Sp4 and I could not see this behavior. Can you replicate with sample content?
Issue with custom code changes