Hello,
I frequently watch two sporting events at the same time by pausing one tuner, watch the other tuner, then repeating.
One thing I have noticed is that the time that a tuner can stay paused before autoplay varies. I am not sure what the pattern is. Sometimes it seems like about 30 minutes and others a few hours.
Any ideas?
Thanks!

This may not be the reason for what you're experiencing, but an HD broadcast is going to fill the pause buffer a lot sooner than an SD broadcast (and 1080i will fill the buffer sooner than 720p).  That could be a factor.