[pvrusb2] Fuzzy Video using Hauppauge WinTV PVR USB2

[cardboil]

I am using the Hauppauge WinTV PVR USB2 card and Mike's pvrusb2 driver, with
MythTV.  When I watch live TV, the picture is a little fuzzy, i.e., when
there is any motion in the video, it starts to look blurred.  Video that
doesn't contain a lot of movement looks OK.

Has anyone else encountered this?  Is this an issue with the fact that the
stream is coming over USB or does it have something to do with my settings
in Myth?  Is there a way to tell Myth to use the card's hardware
encoder/decoder or does that happen by default?

Thanks in advance for any guidance.