I got it working!!!
I tried it first on my sharp zaurus by setting everything up manually, then changing permissions on /etc/resolv.conf to read only. Nasty I know.
Flame me at will!!
I decided to try the same settings on my laptop, but I didn't have to. Once I reactivated ra0 I logged in without any problems. The only change I made was removing "home" from the search list in the network administration dialog.
Other than that I used exactly the same settings I tried at the weekend (I even removed "home" at the weekend, but with no luck)
How weird is that? Never mind, at least my wireless connection is up and running again! It's faster than the old one too