Hi John,
After reading this thread, I'll probaby leave mine on all the time. Normally, I do leave it on. However, during two extended trips (out of the country) more than two weeks each, I did turn it off. After returning from the first trip, it went through what seemed like an extended cleaning cycle after powering on (probably like the one you described). After returning from the second trip, I powered on and it did nothing out of the ordinary, no cleaning cycle or anything. Just printed when I asked it to without any issues. So I'm thiniking maybe it does have a mind of it own about these things
Tony