Strange… here, the “New” task icon is not greyed when I click Tasks.
As for the other icons - when you move your mouse on it and wait a little, you’ll get a tooltip :slight_smile:
The “Edit”, “Delete”, and “Start” icons are greyed out until you select a task from the right part of the window.

I think the “idleness” of the system is recognized by the user typing/not typing on the keyboard and moving/not moving the mouse. I.e. it’s not really checking the CPU usage - so it shouldn’t interefere with folding@home. (I’m not 100% sure about it though - anybody can confirm?)