Cable/DSL Router Not Working

About a month ago I purchased a 'Network Everywhere' 2.4 GHz wireless cable/DSL router (model NWR04B) to split my cable internet connection between my Dell Dimension 8100 and my Dell Inspiron 8000 (wireless).

 

After the initial setup everything worked fine for about a week or so and then one day I had no internet connection on either computer.  I called my ISP and they asked me to unplug the power from both my cable modem and my router and power down my desktop.  After five minutes, I was to 1) plug in the cable modem and let it cycle to 'Online', 2) plug in my router and 3) turn on my desktop.  This did fix the problem.  According to the ISP tech, the router 'got tired' of the DNS addresses and began blocking all activity.  (I have no idea what this means as I am brand new to networking.)  Anyhow, after a few days the same problem recurred.  The problem now is that I cannot repair this.  No matter what order I try powering things up, plugging things in, etc, the connection will not work.  When everything is connected and turned on as it should be (as everything was when it worked initially), the three lights on the front of the router that correspond to the port with the ethernet cable running into my desktop all flash on and off continously once every second or so and I have no internet on either computer.  These lights are labelled 'Link/Act' 'Full/Col' and '100' They are all coming on and going off in synch.  They are not intermittently flickering as though there is send/receive activity on the line.

 

The cable connection is fine becasue when I plug the ethernet cable coming out of the cable modem directly into my desktop's network card I am online just fine.

 

Does anyone know what I need to do in order to restore my wireless access?  It was pure heaven while it lasted. :smileysad:  The router's user manual and website support appear to be useless.

 

Thank you to any and all who may be able to help.

Paul