Good news, my 1TB hardrive is in an external esata caddy so if I need to do a reset I generally drop in the original 320GB drive first. After the reset I simply replace the 320GB with the 1TB and the schedule is still there

I was misremembering. It is the Schedule List you are not allowed to get to when the Play Bar is still on screen (as it is when you press Pause). Curiously this differs from getting to the Media List or the EPG which does allow you access so looks like a spec / coding oversight when considering how to access these three contextually similar functions in this situation. Should be a trivial fix if they ever get round to it.

Anyhow, now I know, this makes spontaneous upcoming timer checks less of a hassle while in the middle of watching a recording.

They've been aware of this since very shortly after the thing came out and had the perfect opportunity to correct it and several other annoyances on the first big update.

As they didn't then and do not appear to have done so with the current beta I think it's unlikely they'll do anything about it now.