Log error was "no space left in the device", or something like "free space below minimum specified". Maybe the program needs twice (or even more!) free space than the file(s) been downloaded in order to complete the decoding and post-processing tasks? Anyway, after closing the program and freeing some space, the decoding process does not continue automatically and all those part files remain in the temp folder. I've tried to cat (type or copy /b) every directory containing part files by hand but unrar throws an error while opening the resulting multipart files saying its damaged. I'm using NTFS and Vista Business 32 bits. May be a button to force decoding (finish processing) would help in these cases...