Hi there, hopefully I can explain myself clearly!
We have a few users now using Outlook 2010 and all the users I have checked have this same issue. The users are secretaries and often send emails on behalf of their authors and they have those authors signatures saved in their Outlooks signatures list. If they type up an email, and in the course of doing this, replace the default signature (their own) with their authors, and then proceed to change the 'From' field in the email to their author, the signature flicks back to being their own (the default). The can be dangerous as they sometimes doesn't notice it happening and then proceed to send the email with the wrong signature.
I originally thought that the email was being reset when the From field was altered, but any other text in the email remains untouched.
We certainly didn't have this issue when using Outlook 2003. Anyone with any ideas on how to stop this happening?
Thanks in advance!