Can't create a digital signature for someone else to sign.

I’m using Adobe Acrobat Pro X version 10.0.0. 

I am trying to create a digital signature block in a .pdf document that someone else will digitally sign using Adobe Reader.  I will send the document to another person who will use Adobe reader to insert their digital signature in the blank digital signature block I created. 

I created the pdf document from an MS Word version 10 document.  I created the pdf formatted document by  using the “Save as … Reader Extended pdf … Enable additional features” path.  I created the digital signature block by using the Tools dropdown menu; selecting “Sign and Certify” and then selecting “Place Signature”.  I use the mouse to “click and drag” an area where I wanted the digital signature block to be. 

At this point Adobe Acrobat won’t let me save the document with the blank digital signature block.  It tries to force me to put my own digital signature in the block instead of allowing me to save the document and send it to my client for her digital signature.

What am I doing wrong?  I’ve successfully done this before on many occasions.

Thank  you.