Internet Explorer 7 forms data problem

I have a user who when opening one of our website's interactive .PDFs
experiences her form data being saved. By this I mean if she clicks on the
form link, types some data, closes the form, then reopens it; the data she
typed is still there. I have deleted her full auto complete history, made
sure she did not have any of the auto complete features selected, reset her
internet explorer settings to the original defaults, but it has had no
effect. My next step was to re-install IE7. Any other ideas?