Accessing contact's custom properties in a Outlook 2007 form region

Question

We have added a form region to contact details form where there are some winform controls which we have data bound to contact custom properties. There is a separate app which creates contacts in exchange server (2003) for different mailboxes using Web Dav protocol. While creating the contact it creates these custom properties also. When I read the contact properties using Web dav from exchange server, I get all the values that I initially wrote. But the same in not showing in Outlook from region. We are using ContactItem.ItemProperties which we get from ActiveInspector.CurrentItem to read those custom properties in the form region. I have tried ContactItem.UserProperties also, but even that does not work. Am I missing something here. Thanks in advance.