Epson 635 printer won't install via wireless with Mountain Lion

I am helping a friend with the upgrade to Mountain Lion and She has a giant desktop which I think is a MacPro but I'm not sure. Anyway everything works fine except now her Epson 635 printer won't see the wireless network. To me this seems like a router problem but all other computers see the network via the router. Also, this only happened with this upgrade. We've uninstalled and reinstalled the printer, drivers, etc and still no go. Forgive me if my lingo is off but I am a tad new to Mac. Does anyone have any ideas? Thanks!