You two are describing two different issues. DiscoStu is saying the Tablo channel on the Roku loads the 24 hours live TV grid upon opening of the channel, then after 24 hours of leaving the Tablo channel open, the guide is not empty. The reason is that the Tablo channel is not 'refreshing' the live TV grid with data from the Tablo. To have the live TV grid refreshed, he has to exit the channel and re-open it.
What you are describing is actual information missing from the guide data so you have to force the Tablo to go out to the internet and download the new updated guide data. Your few time slots here and there missing the guide information would be seen across all platforms, Roku, iPad, Android, etc.