A digitally signed form does not display the digital signature in InfoPath 2003
A hotfix is available to view or print the digitally signed InfoPath 2007 form when the form’s digital certificate expires
When you open a digitally signed form in Microsoft Office InfoPath 2003, you see the following error message where the digital signature should be:
There is a problem with this signature.
You cannot determine who digitally signed the form unless you click View details. If you click View details, you will see the name of the person who digitally signed the form. Additionally, you receive the following error message:
This digital signature has expired.