I have my 625 for use in the single mode. I was recording something on the second tuner while watching tuner 1. The red light came on at eight to indicate I was recording on tuner 2. At 8:05, tuner 1 changed to the channel I was recording, and started recording a second copy of this show. I had to tell it to stop recording to get back to live TV. It luckily only stopped the new tuner 1 recording, and I was able to salvage my tuner 2 recording. Anybody ever have anything like this happen?
