Sounds like motion artifacts from HDV compression. To record HD onto a minDV tape, you've got to go through a LOT of compression. I think your camcorder has an HDMI output. If you could go directly from that to a hard drive, recording uncompressed HD, that should get you a professional video look, without motion artifacts. Of course, you would need a very large hard drive to hold all that uncompressed HD content. Check out the "Convergent Design ships HDMI to HD-SDI converter" blog entry on this website. I'm not sure what hard drive setup you would need. Might check the Focus Enhancements website. I think their FS-100 recorder for the HVX200 can record in some low-compression formats.
Hope this help. :)
Ken Hull