When I first installed LM8 I had real issue with my wireless connectivity which resulted in me reinstalling LM7 with which I had no problems and then I beefed big time in the forums.
I promised that if I found a fix I would post it. I found a fix so here it is.
Just to recap. I have a laptop using an RT73USB based wireless connection but I believe this fixes issues with quite a number of wireless chips.
The issue I saw was a very low signal strength in my lounge (35% from two routers in the roof) and poor or no visibility of the wireless networks. I also tried a Mandriva Linux Live CD and experienced exactly the same issue.
After reinstalling LM8 onto a formatted PC to ensure there was no conflict with previous installs I still had the same issues. After some frustrating hours working on this in my lounge I had a eureka moment: "Take the laptop upstairs!!". I did and lo, the signal strength improved to the point where I could receive a connection and get updates - hurrah.
It proved that the signal strength was probably correct and for some reason LM8 was not treating my wireless connection in the same way as LM7. Armed with this information and Google I was led to the following suggestion from here http://ubuntuforums.org/showthread.php?p=8389047
amongst other places.
In a terminal window type "sudo apt-get install linux-backports-modules-wireless-karmic-generic"
I tried to get more information on this package but as I write the Ubuntu sites seem to be down. There appears to have been a bug discussed at length here https://bugs.launchpad.net/ubuntu/+source/linux-backports-modules-2.6.31/+bug/414560
. The best description I could find for the package as a whole from here http://sprayfly.com/tag/backports/
is "This module contains all the cutting edge wireless drivers for Ubuntu Karmic from the testing repositories which haven’t yet been officially released."
Although it's a backport I decided to give it a go. After re-starting my laptop my signal strength improved from about 45% upstairs to 75% / 80% and from 30%/35% downstairs to a solid 60% as I write.
I have rebooted my PC a number of times and all remains well
I hope that this information helps other folks out there with this or similar issues.