Further information on my question about the epson wireless printer and macbook.
It seems that the epson xp-400 works wirelessly only with 802.11n wireless network not with 802.11g or earlier.
Does anyone else know about this. I read it on the epson support site for epson xp-400.
Also epson xp-400 will not work wirelessly if it is already connected to a computer with a USB cable.