I've never heard of anything like this before. I'd suggest that you go down two paths.
Self-diagnosis: Try a few things with the form. Your email doesn't make clear whether you're using Acrobat with the reader-extended form or you've moved over to Reader. I'd try it both ways. Also, when you reader-extend, just give it every right, like import/export form data.
When you give up: And then, if all this fails, I'd contact support, pointing them to this thread.