I've upgraded a production G2, as well as one in our lab here. When I upgrade from 1.0.0 to 1.1.0, the Guest network seems to not be able to route it's clients. Since the G2 hands itself out as the DNS server(more specifically the gateway of each network), the guest networks gateway doesn't seem to work.
For example, I have a fresh G2 out of the box that I've upgraded to 1.1.0, the "Home" SSID works fine, but the "Guest" SSID will only work if I statically assign our DNS servers, Google's, etc to the clients. It also works if I assign 172.16.1.1 as the DNS server, but it won't work with the native 172.16.2.1 server handed out via DHCP.
Has anyone seen this issue? Also, is there a way that we can manually specify the DNS servers handed out via DHCP in the G2?