Help! I just switched internet providers. My prior one had a modem/router combination that you were obligated to use. The new one does not. So I had to dig the couple year old Motorola Modem and Airport Express from the closet. I have hooked them up, and set a password. The MBA connects to it okay, and can access the internet (although the airport frequently pops open and has two error messages). The ipad and iPad mini cannot access the internet at all. The two errors that the airport utility gives are: 1) Internet Connection - The Airport Express does not have a valid IP address. 2) No DNS Servers. Any ideas how to resolve this?