Canon Printer not detected on new xFi Gateway router

I hve been a Comcast customer for several years, and just got upgraded to a new Gateway xFi modem/router (we have triple play with TV, internet and phone).  Everything has been working great (love the new higher internet speed and "built-in security") but now my printer cannot be detected on the network.  It was working fine on the old network, but not on the new one. 

I have an old router that I used as a 'booster' before this upgrade, so I connected it to the back of the new Gateway, and when my laptop and printer are both connected to that network the printer works fine.   It is an OK fix, but it would be nice to not have to have two networks going at once.

Any ideas as to what might be preventing my printer from being detected on the Gateway network?

Thx, Steve