General :: Use Franklin U301 Aircard Without Network Manager?

Using Network manager, I have been able to use my Aircard to get on the internet. However, many times, the connection is dropped after a short time (<1min), I can reconnect after waiting about another minute. After going through this cycle a couple of times, the aircard stays connected. Since Network Manager doesn't use the "normal" config files for network interfaces I have been chasing my tail trying to figure out what is going on.

Have recently added a router to my system Linksys Model BEFSR41. Now, I can connect to the internet with the aircard but firefox will not find the internet unless I disconnect from the router. Some website have stated that Network Manager is not meant for wired networks - not sure why since there is clearly a tab for that.

In any event, I would like to get rid of Network Manager and just use more normal config files for my networking. Before I delete Network Manager, I want to make sure I can access the internet through the aircard. Does anyone know how to do this? I've tried PON with various settings but don't seem to be able to get anywhere. No DSL, cable or other inet connections in my neighborhood. Aircard is my only (affordable) option.