Stomo11,
I would first check, if you can, with a DT 900 or a DT 901 in a store firstly. As I said my L830 will not charge properly with the Nokia CR 201 and I blame the 830 because my 720 did and still foes charge perfectly in the car.
I have both the 900 and 901 and my L830 charges fine with some room to move them around. I was going to upgrade to the 903 pad; I will not now because I do not want a replication if what is going on in the car. It seems to me there are less coils in the 830 back plate or they are not in the correct position. Please do try the 900/901 chargers if you can and report back. We need to narrow this down in a logical way.