I had bragged about my new "Headline Animator" from FeedBurner.  After going into Outlook, creating an email (using Word as my Editor), I gladly pasted my animator into the signature editor, and showed it to many people.  But I noticed that after a couple of days, it was not showing my new blog entries (note - it's purpose is to show the last 5).  I could see the one in my blog showing the recent blogs.  After some looking at the source in Word, I noticed that Word was using a local GIF that it had cached.  After some looking around, I blindly found this route to verify the HTML in my signature.

I went to Outlook’s menu (instead of Word's menu when editing an email),  Tools | Options | Mail Format tab | Signatures | select a signature, click Edit button, Advanced Edit, answer Yes to external editor (which fires up another copy of Word), click on View menu, HTML Source (which fires up the Script Editor and shows the raw HTML of signature), and then make sure your SRC attribute value is pointing to their server.

Hopefully, this will take care of it.