Got the the breaking point with my current setup and the constant stuttering and freezing when attempting to playback content and broke down and improvised a solution.
What I did was to purchase a Cat6 (Cat5e would do too) patch cable to connect the non-pvr STB to the 2wire gateway. This made the recorded content section disappear completely from the stb as the pvr was still connected by coxial cable. I then used a second patch cable I had that was being used for a wired network drop to hook up the pvr directly to the 2wire by CAT6 cable.
End result? Perfect PVR playback regardless of which stb I use or the type of content (SD and HD).