I made a big HOWTO post on my Nokia 770 blog about using Orb with the Nokia 770. That's here:
http://thoughtfix.blogspot.com/2006/07/stream-anything-to-your-nokia-770-with.html
It seems to work well except...

I am having this problem with certain XVID files streamed over Orb to the RealPlayer in the Nokia 770. It's a discolored banding. It only shows up in video files (not DVR-MS recorded TV) and not ALL files either... just most recent XVID files. Any advice?

I made a YouTube video as an example of this problem:
http://www.youtube.com/watch?v=IscXUeG5SDY

Additional info:
This does not show up when streamed to a Windows Mobile device or to Windows Media Player on a PC.
All my recorded TV and some other MPEG files play just fine on the 770.
This does not show up when streaming to a Windows PC using RealAlternative.
I am using this XviD codec: http://www.free-codecs.com/download/Koepi_XviD.htm

Thanks for your blog entry.
Regarding your problem my only advice would be to try another codec.

Do you mean a different CODEC on the media center PC? Something other than that XviD codec? Any suggestions?

Yes, the codec on your PC running Orb.
We have this FAQ on codecs:
http://support.orb.com/support/solution.jsp?sol=144
but there may be other ones to try.