Digital BW, The Print

I am unable to have raw files open automatically in raw format when downloaded from my d300 camera. My working system consists of: Windows XP, Photoshop CS3 with camera raw_5_3, dng converter5_2. The files do not open automatically with or without conversion to dng. I have no problems with my d70  raw camera files opening directly with the above system. Is this a problem with the camera, or something else? Would appreciate some help.

Bob