I guess you're asking about
Blackmagic Intensity Pro after switching from
Hauppage HD PVR.
Basically both HD PVR and Intensity Pro can record 720p or 1080i video only, they both do NOT support 1080p. While Intensity Pro allows to connect your xbox not only via component video, but also via HDMI, you may not notice any difference compared to recording from component video with HD PVR.
If you don't see any picture in Media Express or VirtualDub, make sure that Intensity Pro drivers are installed. Also make sure 720p is used on your xbox, since Intensity Pro doesn't support 1080p videos.
Intensity Pro has a video path through, so you should be able to connect your HDMI output of xbox with the HDMI intput of Intensity Pro, and then connect the HDMI output of your Intensity Pro with the HDMI input of your TV. The only problem with this type of connection is that the preview windows of Media Express doesn't show any picture, although there is no problem recording your gameplay. I don't really know whether this is a bug or feature. But I can tell you for sure that Intensity Pro doesn't use HDCP when outputting your gameplays.
To solve the problem with video preview in Media Express, you can use an HDMI splitter. Connect your xbox with an HDMI splitter and connect your splitter with your TV and your Intensity card.