Printer won't work after security set up

Hello,
I set up WEP security on my wireless netowrk and now my printer will not print. When I disable the security the printer works agian. Can anyone tell me what I need to do to have security and be able to print?
My computer is an Acer extensa 5420 with Vista, and the printer is a Epson Workforce 600, and I have a linksys router. Thank you!