This is a weird one - I was watching the live TV buffer today on my P4 - (no other tuners being used), and had scheduled to record something on the same channel I was watching, starting soon.
I was probably 20 minutes behind real time in the buffer - when the recorder commandeered the tuner I was viewing and re-changed the channel - (to the same one I was watching) and started recording.
No other tuners were being used.
The entire buffer was blown out and skipped up to the current real time moment as it began recording. As a result, that 20 minutes I had left queued up were gone.
Why didn't it user any one of the other idle, THREE tuners just sitting there?