Tracked Opens # not showing up on CiviMail report page & no forwards tracked

Nothing is showing up to the right of Tracked Opens on the CiviMail Report page for a sent mailing. However, clicking on the Tracked Opens does give the appropriate detail information.

I'm not seeing any indication of a forward even though I forwarded this e-mail to an e-mail not on the original send list. The recipient of the forward opened the e-mail and did click on a link which is reflected in the report information. Is there anything special I need to do when forwarding an e-mail to make sure it gets tracked?