I have a Latitude D400 with a Dell True Mobile 300 Bluetooth internal module.  I cannot get the radio to "turn on".  When I right click on the icon in the system tray and go to "enable", a window pops up that says to use the Fn + F2 keys to turn on the radio.  When I use those keys, it has no effect on the bluetooth and does not turn it on.  It only turns off and on my wireless internet.  I've tried everything from uninstalling and reinstalling the drivers and software (multiple times) from both the website and my install disk that came with my laptop, replacing the bluetooth hardware piece, and Dell even had me send my laptop back to them to replace the motherboard to see if that may help.  After talking to 10 Dell support technicians for a total of over 10 hours and also having my computer sent in for repair and returned in the same condition (I don't know why they didn't test it out before sending it back to me), I am about to give up.  Does anyone have any solutions?  The support guys at Dell have said they don't know what else to do.  I saw a cached message on Google from a guy who had the same problem, but I couldn't see his solution.  Here it is, if you're interested:  http://64.233.161.104/search?q=cache:wAYXT_opkkEJ:delltalk.us.dell.com/supportforums/board/print%3Fboard.id%3Dinsp_network%26message.id%3D23601+Dell+Wireless+300+Bluetooth+Module+XP+service+pack+2&hl=en&gl=us&ct=clnk&cd=1