Open the Info panel (Window > Info) and click on a graphic. You can view the Effective (scaled) Resolution.
Also, make sure you choose View > Display Performance > High Quality Display to view your images at the highest resolution.
Sounds to me like the links are not holding properly and ID thinks they are out of date or missing (have you checked the links panel?) If that's it, it's probably some other software running in the background.
I think you are unfortunately right, I have checked the links panel and nothing seems out of the ordinary there. Wonder what other software could be causing it? I also wonder if starting the document from scratch would alleviate the problem? I am unaware when this document was originally created, however it is used to print our bulletin for church every Sunday and has been saved over and over again. Just the front graphic (the one I am having issues with) and wording is changed.
Thank you Steve for your suggestions, it helped with the on-screen resolution, but it is an issue when printed.
First, export the file to .idml and see if that helps. See Remove minor corruption by exporting
You really need to create a template file for this bulletin. Continuous "recycling" of files eventually leads to cumulative error buildup and disaster. By using a template that contains your pages, colors, styles and anything that remains constant from issue to issue you are always using a second-generation file that should be error-free.