It looks to me like you have some frames onthe master pages that have been overridden onto the document pages, either manually or by placing text into them. It's normal under these conditions, when adding a single page mid-document that as the following pages change sides the master frames for that side are re-established behind the overridden frames.
Thank you for respnding so quickly.
How do I fix my problem? I did add to the master pages but my additions didn't include columns.
You don't really "fix" the problem, you avoid it by only adding pages in pairs. Alternatively you can override the master items again and delete them, but that's a real paiin when they are behind other things (and master objeccts are always behind non-master objects on any given layer).
And you aren't really seeing two columns. Waht you have is two text frames on top of each other, one with left aligned text and one with right aligned text.
Thank you, it worked! I will bare your advice in mind for future projects.