Barnie - Have you fixed it yet, the reason I ask is i have a very similar problem. I have a NWHD1 and was importing some MP3 files (which were located on my PC Hard Disk) into SonicStage 3.3 when the Application Crashed, I restarted and got the message - checking if tracks were deleted without being transferred. I then got the annoying OK, OK, OK Message Prompt Loop. I uninstalled SonicStage 3.3 and did a fresh install of 3.4, same problem got the message - checking if tracks were deleted without being transferred. I then got the annoying OK, OK, OK Message Prompt Loop. I then did a factory settings restore on the NWHD1 and a Format. same problem got the message - checking if tracks were deleted without being transferred. I then got the annoying OK, OK, OK Message Prompt Loop. I then uninstalled SonicStage 3.4 and reinstalled a fresh copy of 3.3. I also cleared out the Sonic Stage Database so my librayr only has 5 tracks (which I freshly imported from CD's). Now when I connect the NWHD1 it shows up as having 18.6GB Free which is correct. I go to transfer a file and I get an error. something along the lines of cannot transfer to device. i then try the same file again and i get the error saying that there is no room on the NWHD1, I checked under device settings and sure enough it shows up as 0kb free. I have repeated this and everytime 1st transfer fails due to an error, second transfer fails due to NWHD1 being out of space. I called Sony support who werent really any use, they said they'd never heard of it and i need to install the software on another PC to try and see if its my PC or the NWHD1. Any help would be grateful, failing that i am going to install SonicStage on my laptop, which has a fresh copy of XP on it and i'll see how i get on.