|I've had issues with my laptop networking not working right when it was too close to the Router's antenna. Probably from an overloaded signal.|
Another thing to look for is what wireless protocol is the printer using, IE. 802.11b, 802.11g, or the latest 802.11n. Make sure your router supports it. The most common protocol right now is 802.11g. Check if both the router and printer are using that one.