I had this same problem. If I reset it, then it would work for a little bit, then cut out. Try following this procedure:
1. Configure the router and as follows by going to
http://192.168.1.1
Basic Setup:
Internet Connection Type: PPPoE (contact your DSL provider for your userid and password.)
Keep alive selected
Then save the settings.
Wireless Tab
Basic Wireless setting:
Wireless channel : 1, 6 or 11
Advanced wireless Settings:
Set everything to the default expect the following:
Beacon interval to 50
Fragmentation threshold and RTS Threshold to 2304
Then save the settings
Load the firmware update given at Linksys.
2. Then follow the powerdown and power up procedures. Very important you follow them exactly.
* Shut down your computer.
* Turn your modem off(either by unplugging the power cord or by using a power switch on the modem).
* Unplug the power cord from the back of your router and confirm that the front panel lights turn off.
At this stage, all devices (your modem, router, and computer) should be powered off.
* Wait for about 30 seconds.
* Plug in the modems power cord. If there is an additional power switch required to power on your modem, be sure to use it to apply power and turn on the modem.
Observe the indicator lights located on the modem and wait for the lights to stop blinking. A light indicating Power as well as DSL (or Internet, Online, Ready, etc.) should become solid to indicate a connection to your Internet Service Provider. The names of modem lights will vary depending on modem brand and model.
* Next, plug in the routers power cord. After a few seconds, the Internet light (or WAN lights) on the front of the router as well as additional lights on your modem should turn on to indicate a connection.
* Turn on your computer.