Given the fact that correct W06 BIOS is installed, it sounds more like a regression in Natty. For a simple verification, can anyone with the hardware in hand just install Maverick and Natty and see if the bug exists in Maverick? Last time we were fixing in Maverick.
I will try to verify when I am able to reach my Latitude 2110 too, as it has the same bug, though this bug is for Latitude 2120.
It will be helpful one can attach the log of `rfkill list` and /sys/kernel/debug/dell_laptop/rfkill at both the moment when the radio is enabled and when it is disabled (or locked in this case).