I get online, then drop signal

I'm using the WiFi Ranger router, and their customer support is excellent. I can't reach anyone today, however, so I thought I would come over here. I have Win 7 Home Premium and use the router via LAN cable. I live in an RV campground and depend on Tengo wifi to connect. After a firmware upgrade for the router, my consistent service deteriorated so that I can connect, but the signal will drop after about half an hour. It's been doing this for days on end. I also note that my ZoneAlarm has had some major feature changes. I'm wondering
if something is going on between these two. There's a new "enable OS firewall" feature.
Default is to have it checked as "on" Also, in custom program settings the default position is to have "allow outgoing DHCP" unchecked. I know that my router shows a DHCPing process when it connects. I don't know what any of this stuff means (I plan to read up), but that would seem counter-intuitive. Wouldn't I want to allow outgoing DHCP? I realize that this question is a large uncharted terrain but perhaps someone has an insight. I'll be calling customer support at Ranger asap.

Thanks

2 firewalls running at the same time normally causes all kinds of hair pulling.