The skip back button is pretty inconsistent on my 722K. Sometimes it will skip back 10 secs, 30 secs, minutes, and even to the beginning of the recording. It is not prejudice to any channel. It happens with both TV1 and TV2. Currently they are both connected to SD tvs. My software is at L655. This is also my second 722K, the first was replaced to fix this issue which obviously did not work.