Microsoft Outlook email - ActiveX Message on Signature Insert

Hi,

I've developed a signature in Word, with 2 graphics, and saved it as a web
page. I've saved in the Microsoft/Signatures directory, and it has an
associated folder of files. My staff have all followed a process to tailor
it and save it on their computers. Every time I or one of my staff inserts
their signature, we receive the message: "Your current security settings
prohibit running ActiveX controls on this page. As a result, the page may
not display correctly.". A small little transparent box appears in the top
left hand of the signature, which we need to delete. From what I can deduct,
if we delete the little box, we no longer have the ActiveX message appear.
If a staff member doesn't delete the little box, and sends me an e-mail with
their signature on it, the ActiveX error message appears again.

I don't know anything about ActiveX. Have I somehow during file creation
included something ActiveX? I've looked up a definition of it, and it seems
to be related to movement. There is no movement in the signature.

Basically I'd like us all to stop receiving the message, and needing to
delete the little box. Can anyone advise me, either relating to some setting
in Outlook, or what I've done wrong in Word creating the signature?

Thanks,