Bought a wireless multi-printer last month (Canon MX420). Hooked it up to the network, and two other computers were able to find the printer (wireless) and print a test page. All was fine until about 20 minutes later when I tried to print a paper from upstairs. I kept getting a "printer offline" message. If I went downstairs and tapped the on button and ran upstairs, it would then print. When the printer sleeps(?) it's offline to the 2 wireless computers. I've deleted the printer software, unplugged/rebooted everything and all the printers print, until the printer sleeps after 5 minutes. Any ideas?