Issues with Previewing

Hello all!
I’m a relatively new Axure user (3 months or so) but I’m having issues with Previewing certain pages in my current project.
Certain pages don’t seem to want to Preview or won’t link to other pages. I had this issue before and I managed to resolve it by removing the offending pages from sub-folders in the project. I tried this again but it doesn’t seem to help this time.
The strange thing is that the pages don’t even appear in Project Pages menu when I Preview.
Is this a bug or am I just being really stupid!
If anyone can shed any light I would be most grateful!

I have just managed to fix it!
If anyone else is having the same issue you need to Configure the pages to display in the Preview Options under the main menu.