Canon MX340 not printing

Hi, I have a new Canon MX340 who is showing up in the print prefs, but is not printing. It states off line. It's a wireless printer, so I figure it should be picked up by both a windows vista computer and the iMac dual core intel in the house. It is printing from the windows computer, but refuses the mac.
I have never seen the off line message so I am clueless of how to proceed...
Checked out the system prefs, printer is shared and shows... What is the next step?
Is this printer plug and play or should it have a special driver? Any insight would be greatly appreciated...