This seems to be new behavior to me. I'm pretty sure it is, but I may be wrong.
I leave my p7000 on all the time. Sleep Mode after 210 minutes. When the printer wakes up, it usually pumps air to charge the lines (I assume) and then it's ready to go. Recently, upon waking up, it charges up, but then immediately releases the air pressure. I don't remember it doing this prior to a week or so ago. It would usually stay all charged up, until it went back to sleep. Seems to print normally.. It does seem to have a longer pre-print routine tho (head scanning and moving around). Hopefully not an indication of some sort of problem?
John V.