Really odd WLAN problem

My old Dell 8500 laptop has developed a very odd problem.

After "upgrading" the driver for a USR 5410 WLAN PC card, it's stopped working.

The card picks up the local wireless routers, but can't conenct because the IP address is not applied.  The state is shown as disconnected & IPCONFIG does not return an IP address (manually set in the settings dialogue).

I  bought a new HDD & re-installed the OS (XP-Pro) - which along with a memory upgrade was planned.

I've tried all 4 versions of the USR driver (updating XP as necessary).

No dice.

Basically, no IP address is being applied.

I have tried it in the office with a fixed IP & at home with DHCP. No joy.

The static IP address is being sucessfully assigned, as I tried to set the NIC with the same IP & windows displayed an error, idicating that the IP was in used.

I ran the NIC utility which showed that it (the NIC) was assigned memory slot 2, 0, 0 - which tied up with the info in Device Manager.  I checke the tab for the WLAN card & it showed many firelds as not available, one of which was the memory slot - Device manager shows it as 3, 0, 0 - both have IRQ 11 (along with the PCMCIA device & USB controllers.

Every serch on Google returns the same advice - mess with the Router, WZC, assign an IP manually, try switching on & off.

I've run all the Dell diagnostics with not failures.

I know the card works because I can use it in another laptop.

Anyone got any ideas??