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.
Also, anyone reading this should note that this issue is also posted in Process Management and Workspace
