ekeby2:I don't understand if that's a function of using the same project template over and over for different jobs…
Was the file you are using saved as a template (that opens as an untitled project), or is it just a project file that you are re-using? There is a significant difference. If a file is re-used over and over, it is possible that parts of the code can become damaged, which could cause errors like the one you are having.
If you (for example) have a monthly flyer and save it as a project, July's flyer will contain any errors that happened in June's flyer, along with any that happened May's, and so on. If you save it as a template with just master pages, colors, stylesheets, etc., anything that happens to one month's flyer won't effect the next because you aren't opening last month's flyer, you are opening a copy of the template that last month's flyer was built from.
For this project, you could try thumbnail-dragging to a new project, or appending the layout. That has the possibility of bringing the content to a new file, but possibly leaving the bugs behind.