Hi Phil,
this won't be of much help, but I have seen this happen as well. I never worked out what caused it, but it stopped happening as magically as it started.
I can't remember if it happened only when running the app in the development version or if it happened in the runtime as well.
My first guess would be to delete your resource file and see if that fixes it.
>>>>Do you have the same problem with all reports or some work correctly? If you remove code, that maximizes the preview, would you still have the problem?
>
>I think it is all reports. I'll check each one to make sure.