BSOD Stop Error
The error most probably references the driver for your wireless card. In order to be able to read the error message (in XP ) you will need to go to Control Panel/ System properties/ Advanced/ Settings/ then clear the check box beside "Automatically restart" then click OK. Now the screen will stop when the error appears and you will be able to read it. You also should be able to see the error message in the error log as well as the System Events Log.
I have had the same problem with my Area 51 m Extreme since I received it about 2 months ago. I was using a Microsoft MN-720 802.11g adapter with a Broadcom chipset. If you visit the Alienware Customer Forum you will see that you have plenty of company. You might also notice that most if not all of the wireless adapters that have this problem, use a Broadcom chipset.
I just received a WLAN a+b+g adapter with an Atheros chipset. This new card has been in use since Monday without a problem. This is the longest it has gone without the BSOD in all the time I've had it. Technical Support seems to agree that the problem lies in the chipset. They promised that they would contact all users who had reported this problem and work with you to correct the problem. If you have not been contacted, then contact them and keep badgering them until you get the correct response. This is definitely a case where the squeeky wheel gets the grease.