Let me start by saying thank you, again, for participating in this forum.
I can't attribute this to anything I did. I have extensive electronic and mechanical troubleshooting experience so I know what you are looking for but I am not able to offer any ideas as nothing comes to light.
The events that lead up to this were: two recordings on HD channels were occurring at the same time so I was watching a third that was recorded (obviously). I had no problem with the recording I was watching. I did pause the recording while I was watching it when the phone rang but this didn't seem to have any effect when I tried it again later. I simply tried to play each of the two recordings in turn and when it reached the 27 minute mark, the 'loop' happened on both of them. I could REW but not FF from that point. No matter how far I went back, both recordings would only play to the exact same scene and then enter the 'loop'.
One thing I did notice was when I tried to show this to the tech who came, the recording would not do the 'loop back' but just skipped to the very end and would not allow viewing of any of the last half hour. I can only attribute that change to the fact that I did delete one of the two recordings as I was getting over 90% capacity used the next day when I was trying to record another program.
I don't know if any of that helps but I simply wasn't able to replicate the same problem, no matter what I tried. FWIW, I am one of the 'lucky people' who seem to get all the 'bad luck' and 'if anything can go wrong, it will'. I don't live 'under a cloud' but have come to accept that the world is not a perfect place and for some reason, I am usually there when things go wrong.
As a consequince, I have pretty low expectations but still seem to get dissappointed on a regular basis.
Since that box is no longer in my possession, I can't do any more troubleshooting but if I can ever be of assistance, please just let me know and I will be glad to help in any way I can. This same offer to Shaw has gone unappreciated so I won't be surprised if you don't ask me for anything else either. I know the bigger problem is with their head end equipment but that should not have caused my problems. I'm going to attribute it to a bad hard drive and just keep my fingers crossed that the replacement Aspen will be problem free.