Outlook 07 not working with InfoPath 03

We have a form routing solution involving InfoPath, Outlook, and SharePoint. Some users were upgraded to Office 07, but still have InfoPath 03. The issue is that a radio button on the InfoPath 03 form that connects to Outlook Contact list to fill out a name section does not work when the user has Outlook 07. Is this a known issue, or should we just make sure everyone gets InfoPath 07 when the networking people are doing these upgrades?
THANKS!!