Attach files to editable PDF form then save as issue

I'm setting up a series of grant applications as editable PDF forms.  The applicant will download the PDF and open with adobe reader, fill it out, attach files with essays or charts, then save as. I have an Attach button that: View/Show/navigation pane/attachments and then calls the attach function.  The File/save as button just calls the file/save as function.

On most computers, this works fine. But on some computers, the file/save as button doesn't do anything. If the applicant goes to the menu and chooses file/save as, it works fine.

Any ideas on what might be wrong? I'm not sure where to start looking.

Here's an example:  Submit Jefferson Grant -

Thanks for your help!

Mona