Printer Shuts Off

I have an HP 2575 All-In-One and recently set it up to print share using a USB connection in conjunction with a wireless router with an XP computer and a Vista computer using a program called Network Magic. I was successful, eventually able to get both computers recognized by the printer and was able to print. I didn't want to reinstall the printer software to network it totally using the wireless router and the USB connection gave me a backup if my cable signal went down...I would still be able to print. I posted this problem on the Networking section but after having 3 chat sessions with HP techs, last one telling to disconnect the computer from the network and leave it in stand alone mode...same shutdown problem after about a half hour without any warning the printer just goes off. I can put it back on using the power button. Is there a power save feature on the printer that I am unaware of, and if so I can I reset it or turn it off? Is there a power management feature on the printer? Could this problem be caused by a software or XP Vista connection or Vista bug?...virus?...or is it time to get a new printer?