07.13.2009 at 11:15AM PDT, ID: 24842335
Found this on the Dell support site-
Just bought 4 E6500's (Win XP)with the same issue.
I believe I found the fix. It seems to be caused by the Control Point Connection Manager installed by Dell.
This worked for all 4 of mine:
1. Uninstall Control Point Connection Manager and reboot.
2. Go to Dell support Drivers and Downloads. Download and install the appropriate wirless networking driver for your system.
3. Reboot. The Dell wireless management tool should open on boot. Select the utility and uncheck "Let this tool manage your wireless networks".
You should be good to go. I don't think Dell has the Control Point application working properly yet."

I'd ask Dell for some dollar coupon/credit for your troubles.