I don't see how it could be interference since it's happening every single morning. We don't use any cordless phones or walkie talkies. The network does not even show up in my iPhone until I restart the router.
As for the DHCP, again, wouldn't the SSID show up in my iPhone's list of networks? Once I restart the router the iPhone, and the desktop computer, both connect immediately.
I will try the channel suggestion, though.