TeleFragger

Ok so I have been using my 3955 with navman sleeve for a while now.. love it...
however I just started using my pda as a mp3 player too since i have the external addonics brick setup with a 20gb drive.... well it all works just great.. however when I have power into my pda and use the fm transmitter.... I get alot of staticky noise.. thought it was fromt the channels I use since it is a fm transmitter... however I have the belkin car/usb charger sinc cable... this weekend I hit the button for charge or sync on the cord and when the pda was not in charge mode the mp3's were CRYSTAL clear!!!! so the problem isnt the transmitter but the pda while charging.... anyone else have a problem like this and is there anything to do about it?

I have tried that cable and a normal car charger with round plug to pda adapter plugged into pda while pda was in navman sleeve
tried both adapters plugged into pda and or dual compaq sleeve...

now I only have 1 dc plug in the car so I have a 4 in 1 lighter kit.... I think I remember it was just as staticy in our trailblazer which has 3 lighter plugs...

any ideas?