I have been having a problem with my Zoom DSL-modem/wireless-router, serving two computers in my home. The desktop box is normally connected via an Ethernet cable. The laptop had, for several months, been connected via wifi.

The first six months I owned the laptop, I ran it with the Windows XP Pro OS. Last July, I re-formatted to run Ubuntu Linux (v. 8.04). For the first couple months on Ubuntu, I had no problem connecting to my wireless network or to other wireless networks.

Suddenly, sometime in September, I was no longer able to connect to my wireless network. The network manager will see the signal (the encryption type, the broadcast channel, etc.) but it doesn't connect. I upgraded to Ubuntu 8.10, but still no wireless connection. I re-installed 8.04 (excluding the up-grades), but still no wireless.

There are other, unsecured wireless networks in my neighborhood, and I have been able to connect to them. I checked the broadcast channels on all of them, and none are set to use the same channel as my system.

I can put my laptop on my computer desk, plug in an Ethernet cable, and be connected to my LAN and to the Internet through the wired connection, but even that close to my router (about 1 meter), still no wireless connection.

I tried connecting wireless with from my desktop box (running Windows XP Pro): shut down power, unplugged the Ethernet cable, installed a wireless card, and powered back up. Same result as the laptop -- my wireless network is visible, but it won't connect.

I've tried shutting everything down -- both computers and the modem-router, then re-booting the router first, then the computers (after the router shows full connection to the Internet). Still no joy.

I've uninstalled the Network Manager that came with Ubuntu and installed wicd instead. That shows me a little more detail, but I still cannot get a connection with my wireless system. The wicd window shows a message "Configuring WPA Authentication code" then "Validating Authentication" but after showing that message for a minute or so, the process stops and I'm still not connected.

I tried re-setting my router to use no security--neither WPA nor WEP--but still my laptop sees the signal but will not connect.

Any ideas where I can look further for the source of this trouble?

What is your wireless hardware?

I use the old ipw3945 driver for my hardware - this requires an ipw3945d 'daemon' which often does not load on start and I need to start it or else the wireless hardware will not be able to connect.

If you had the same hardware and upgraded to the 'iwl3945' driver, *but* had the older ipw3945 firmware, then the wireless will not work either. In such a case, updating the firmware to the version which works with your kernel driver would fix things.

The router is a Zoom ADSL X6. The documentation doesn't give any more specific details.

The hardware in my laptop is a Broadcam BCM 4318 (AirForce One 54g) 802.11g. This will connect to unsecured wireless networks in my neighborhood, but it does not connect to my own wireless.

If you have tried two different network cards and two different machine with different OSes and you end up with the same result the issue is likely the wireless portion or your modem, or with settings in the modem. Call the ISP if it is their modem and have them do troubleshooting and if need be get a tech out, I almost guarantee it is the modem. You could also see about just buying a new modem from bestbuy or something and set up your own.