Dell Wireless 1510 WLAN Mini-Card doesn't authenticate computers in 802.1x

We use Dell E6400’s with the Dell Wireless 1510-N WLAN Mini-Card, however, we are unable to perform 802.1x computer authentication. We’re using WPA2-Enterprise with PEAP/AES. Our RADIUS server log indicates that user credentials, not computer credentials, are being sent.

There is no 'Authenticate computer' or similar check-box as in newer versions. Dell Tech Support was no help - they simply said "We've run out of ideas".

Is there a how-to on sending computer credentials that you’re aware of? It doesn’t seem to matter what driver version is loaded.