"The tuner you were using was required for a recording. Would you like to switch ..."

[jpsa]

So far so good: reducing WakeupPreRecordingSeconds allowed the update to start within the two minutes, and it then completed properly over the next 10 minutes or so. I've also had no "The tuner you were using was required for a recording..." interruptions to live TV this morning.

[peejay]

I had this problem too where the computer goes back to sleep straight after waking up. I changed the "system unattended sleep timeout" to 5 minutes and no more problems. The default of 2 minutes isn't long enough for NextPVR to start doing its thing.

Do what Martin says and follow Lao Pan's info.