I've had this f4580 printer for several years. It has several issues, most prominently bogus "media tray is empty" messages and consequent malfunction.
Among the more minor of its problems is:
The power button does not shut off the printer!
Neither a light tap or a more determined push on the power button will work.
If I unplug it, I can use the power button to turn it on (very grateful for that). But the power button does NOT turn it off.
This seems like a hardware problem intrinsic to the printer, but just for information: It's cabled by USB to a Mac mini running OS 10.6.8.
Anyone else have this problem?