Security settings change when rendered from third party Windows 2008 R2 server

Question

We created a fillable PDF form in Adobe Acrobat and made it Reader extended. Opening the form on a local hard drive the security settings show that Signing: is Allowed. We can sign documents in the form with a signature pad.
After we upload it to a third party Windows server 2008 R2, and we later go to access the form, the server renders it back to us in Adobe Reader. We are unable to digitally sign documents in the form with a Topaz signature pad. We notice that although the form was originally created with the form being Reader extended the security settings change to Signing: Not Allowed.
How can we get the server to render the document back to us where we can digitally sign documents in the form?

Answer 1

The second file still shows the extended rights header is present (it's warning you about restrictions at the top of the dialog while also reporting the method is "no security") but the digital signature which grants those extended rights will be invalidated if *anything* in the file structure is changed. I suspect in this case that the server software is doing something to your file; it may be trivial such as adding an XMP tag, but it's enough to break the hash check.