We can't know. you have not offered any technical details. A screenshot would be the best way to clarify. Sounds like you created some object on one of the master pages and it shows up on all pages derived from it, but we realyl need a lot more details...
Moving this discussion to the InDesign forum.
I think, as Mylenium points out, we need a screen capture and more information. I have a hunch you might have chosen View > Display Performance > Fast which replaces pictures with gray boxes.
thank you mylenium, this was the case, object on the master page - but the interesting thing about it: the grey box wasn't there bevor obening it with the testversion - after opening it with the testversion, the box was there, without any other action.
and sorry, i can't make a screenshot, since it is a customers document (wouldn't help, having a screenshot with a grey rectangle on it!?).
so the problem is resolved, but the sorce of it is not. may be one of thouse - spooky computer tings ;-) -
thanks for your help
thank you steve werner for your thoughts!