adding a hyperlink in a mail signature line

I have my websites and blog set as hyperlinks in my signature line. Unfortunately, the link is no longer active in the signature line I use for business communication, although the links are active in my other signature lines.

I go to mail->preferences->signatures and select the business signature to edit. I highlight the part of the signature that I wish to hyperlink, and select from the mail toolbar, edit->hyperlink->add. Nothing happens. I expect the hyperlink box to appear so I can input my web address.

If I control-click on the highlighted text, and choose link->add: The panel that appears is SEARCHING THIS MAC. That's totally incorrect, and I can't see how to force the correct input panel to appear.

Any help?
Thanks,
Kittie Rue Deemer