The two WiFi bands have recently been combined into one with the Comcast gateway devices. Some devices get confused and don't know how to see / talk to combined bands.
If you are not using any Xfi Pods, you can try separating the 2.4 and the 5.0 bands and give them two different broadcast names / SSID's;
Associate the cams with the 2.4 band's SSID (broadcast name) and password.
I have been wondering how to do this as well! The instructions EG gave seem clear enough on how to split out the two signals.
I can't try it right now myself, but I'm bookmarking that page for whenever Comcast gets my service back up & running as I've been unable to use my 2.4 devices since receiving my "New Improved" modem.
Uh... The instructions that I posted are indeed to separate them...