Can you provide details as to how you’ve set up your document? Are you using Facing Pages or Single Pages? Can you provide screen shots of what’s happening? If so please make sure to include a shot of your Pages Panel. Also what version of InDesign and what operating system are you using?
Could be file corruption if it happens to a particular file only. In such a case export the document to IDML and then resave it as INDD. If this does not work try trashing InDesign preferences and cache, it might help