I noticed that if I let the SDrive idle, that after approximately 2 minutes it was like it had powered itself down, and would need to 'wake-up' before disk access was possible. Now I use the term 'powered itself down' which isn't what actually happens (power is present the entire time, and not controlled by the SDrive). Another way of putting it, is that it seems to fall asleep and/or Time-Out.   Here's a video showing what I am talking about...     When the vi