Weird problem. (I know 2 posts in 2 hours but its been about a year since previous post!) The installer worked fine. Having no internet on the new OS was a pig but I tried the following:
Gnome network manager. Quite useless as it doesnt appear to have a detection daemon-?
Plugged in wired network. Nothing
Installer in rescue mode- this time didn't find either wired or wireless. And my router didn't show the device.
Wicd. Had to source build it, can't start from menu but "wicd" from root console then clicking the toolbar icon got the gui up. Wouldn't find either of my networks.

I have a clue. This is a dual boot machine XP/squeeze. My old router used to get confused if I rebooted my vista/lenny box with lenny straight after vista, although not the other way round. This is a new router. Is this router thrown by the same mac address appearing with 2 different names? Should I make sure the host name is the same whatever OS I am using?

I have rebooted into XP and that is still OK, so no hardware problem.

If it gets messy I'm tempted to go for Ubuntu, not imho quite as stable as Debian but might be a bit more friendly? Anyway, advice will as ever be invaluable! Cheers.

Try installing Lenny first then doing an update to squeeze, I'm pretty sure lenny should find your wired at lest. =P That way you have internet for something, and updating to squeeze isn't that hard once it is all working.

probably well worth a try. I can see that KDE control in squeeze isn't quite as easy as it was in lenny so maybe there are other differences too. Thanks.

Yeah I got squeeze to install, but then on reboot it kept giving me grub errors. =( So I got out my lenny 5.02 disc and put that one. I just wanted ext4 installed fresh =( I got ext4 now =D haha

I'm with Ubuntu now as 2nd OS. No trouble picking up wired network, but it only detects the presence of the wireless on the live cd- and even than it doesn't give the 64 bit key as a validation option so I still can't connect in. On full installation, the wireless connection is never picked up. Well I'm stumped!

Maybe I'll get my wireless to work with debian on my PC, though wired still has better speeds. =(

True, but wireless is sometimes needed for laptops. Anyway I think my problem is /etc/network/interfaces, I'll be posting a question on that.