Dell 1397 Wireless mini-card on Latitude E5500 won't connect to WAP

I have a number of machines using the  dell 1397 Mini cards that wont connect to one of our sites

as per the link below I have tried the following

 

* Installed all Windows Updates
* Installed all available driver updates
* Checked BIOS to be sure wireless is enabled
* Checked switch

on laptop to be sure wireless is enabled
* Removed & re-added 1397 card with latest drivers
* Installed another USB Wireless adapter to see if that one would work (no dice)
* Uninstalled all Dell Wireless Management Utilities
* Formatted the C: drive & reloaded Windows XP
* Installed the Dell drivers for all hardware, leaving out the wireless mgmt utility - managed by windows only, still does not work

 

http://www.experts-exchange.com/Networking/Wireless/Q_26230004.html

These laptops then work fine on other sites using the same SSID however other E5500 with the intel wireless connect fine to this WAP.