media center manual recording problem

When I setup a manual recording for the daily news (channel and time), to
start 1 minute early, after a couple of weeks a second instance of the same
program magically starts recording too (I have 2 tuners). This second
instance is not in my scheduled recordings and to get rid of it I need to
cancel the original and wait a day or two for things to reset themselves. I
did notice that one recording is tagged as "My title 5:59" and the second
gets tagged with what appears to be the built in guide's name for the
recording, i.e. "CJOH News". This has happened repeatedly and with more than
one manual recording.