thanks Tacit! You don't need to know about the program to help.
The developer knows the program inside and out and cannot tell me why the cache is stuck on my computer.
HE said he uses Safari tookit -- whatever that means.

This is from my help ticket with him:

To developer:

I duplicated a max blast. Changed some text and swapped in a new image (jpeg)
everything looks great and tests fine. But for some reason the image in the preview within max shows the old image, even though that image was deleted off the server!

Kevs

MaxBulk Mailer uses the Apple Web Kit as Safari. I guess it is a cache problem. Yes but MaxBulk Mailer uses the Apple Web Kit as Safari and the only explanation is some cache somewhere. When you don't see in the preview what is intended, usually something older, it is because of a cache. MaxBulk Mailer doesn't use any but Web Kit does.