Hadn't realized ImgBrun keeps a running log until I went to its Forums... Odd thing is, where I thought the error would appear is not there. Though I think it may have been this. Code: W 10:03:55 I/O Interface 'SPTI - Device Enumeration Method' has been changed! I 10:03:55 Searching for SCSI / ATAPI devices... E 10:03:57 Device->Initialise() Failed! E 10:03:57 Device: [0:0:0] (D:) E 10:03:57 This drive will not be visible in the program. Which to me would indicate that the device may have been in use by a 'phantom' process. Given that I couldn't eject or umount either.