X5: Unrecognized Card

[MelyMel]

I got an X5 for Father's Day (probably from Ebay) and you folks have been a big help, but I cannot get connected to my home wireless network. I get the "Unrecognized Card" message. The green light on the card comes on for a second when I insert it and goes out when the message appears. I have uninstalled and re-installed drivers several times, both with the card in and out, went to Dell's site for an update patch (also thanks to one of the posts on this site), entered prismnds.dll as the device driver, done hard and soft resets many times but nothing works.
My question: Are there some cards which are simply not compatible? I got a Hawking Technologies CF100W (hawkingtech.com). I sent their tech support an email yesterday but have not heard back yet.