I have exactly the same problem. I have a N510 connected to my PC with SonicStage 2.3 on Windows XP SP2. It must have something to do with the conversion, because SS also freezes when I try to convert files in SS without uploading to MD at the same time. I also thought of a codec problem, maybe some 3rd party codec interferes with the OpenMG filter (don't know if this is possible?). The strange thing is, some files are converted without problems, while SS always hangs on others at exactly the same point every time. I tried using SS 1.5 and Realplayer to no avail. RealPlayer gives an error saying that it can't upload the files to the NetMD because it is either not connected or doesn't support the given file format (which I've set to ATRAC3 132 kbs). The latter indicates that it could be a codec problem. Anyone with a solution? * edit * I can add that the Sony MP3 Conversion tool also hangs on exactly the same MP3 files. I already tried to convert the files with WinLAME first (to new MP3 files), using different settings, but SS still crashes (at another point, because it are basically other files, but it still does).