Issue with MRDVR on one station

I have a strange issue when watching back shows from my Whole house DVR on my second STB in another room. The issue is that during playback, at some point in the episoide, the sound will start stuttering.cutting in and out and is sometimes accompanied by video pixelation (minor).  The weird thing is, this only happens when watching shows recorded on A&E channel.  Plus - it happens whether its the HD version of A&E or the SD version.  Playing back on the main DVR works without problem.  I have tried all the obvious solutions, such as using the fix MRDVR options in the menu and rebooting the boxes and cable modem, etc. and still cant get this to work.  I do use an external HD for my storage, but if there were an issue there, i would expect it to happen on all playback and not just A&E shows. 

Any ideas? really scratching my head on this one. i went as far as to replace some of teh cabling between the two boxes (was able to replace half of it) but that had no affect.