I think the net-setup problem was because I had installed over an old SUSE distro and I suppose some things got jumbled.
I did a clean install and as before knetwork manager picked up my wireless network, allowed me to enter my WPA key and connected. This time I could get onto the internet. After 5 minutes or so browsing my emails I lost the network connection and it went back to the old 28% trick.
So I went into windows and disabled encryption and just activated the MAC filter on my router. Still no joy, just 28%.
So i turned off knetwork manager and tried net-setup (which worked this time so i assume it was the clean install rather than overwrite) but as far as I can tell it acheives nothing (I'm afraid i find it a bit difficult to tell whether a zero throughput for the ESSID is supposed to mean it cant see the network or it simply cant send any packets).
I decided to take a shot at following the guide viewtopic.php?f=52&t=2862
as far as possible (obviously some things are different in a predicatable way from the guide such as wlan0 instead of rausb0) though some of the files it suggested editing simply arent created ( /etc/modules.d/rt73 for example is not created and nothing similar is either) and it doesnt seem to achieve much.
I'll have a go at wrangling with ndiswrapper tomorrow, but I just cant understand how it can work fine for 5 minutes and then nothing, it seems a bit much to have to do a clean install every time I want to get online.
gah, I'm ranting.