wireless network connections on Kubuntu 8.04.1

[Lisi Reisz]

I have a MSI 802.11g PCMCIA WiFi card with the Ralink RT2500 Chipset in a Dell 
Latitude p4 connecting - or failing to connect :-( - via a Netgear DG834G v4 
wireless ADSL modem router.

When I first installed Hardy, the wireless card was recognised and both green 
lights were on, but it could only connect with static IP.  After numerous 
attempts over several days, in desperation I tried manually 
editing /etc/network/interfaces.  Still no joy.  I tried a few different 
combinations, including finally deleting  /etc/network/interfaces and letting 
Kubuntu regenerate it.  

So I installed linux-backports-modules-hardy-generic.  One of the green lights 
went out and it would now not connect at all, even tho' network settings 
could still see it.

So I uninstalled linux-backports-modules-hardy-generic (apt-get purge 
linux-backports-modules-hardy-generic, aptget autoremove).  Now the lights 
are both on, but there is no actual connection.

I tried pinging the router.  All packets were dropped.  I pinged the laptop 
from the router and all packets reached their destination.  So I pinged the 
router from the laptop.  Nada.  So I again pinged the laptop from the router.  
This time nothing.  And that is still the situation.

I also tried connecting the ethernet connection via DHCP.  It would work only 
if I told it the DNS to use - it could not get the information from the 
server.  Not much use for roving!!  But the wrieless card could not even get 
an IP from the router.

Suggestions?  I'll try anything, short of throwing the whole lot through the 
window.  I have to get wireless DHCP going on this laptop. :-(

TIA
Lisi