I'm using DD 10 build 2160 under Vista. I'm trying to create a copy of the Vista partition onto a USB-connected HDD. Vista occupies 15GB in a 112GB partition on my laptop. For the copy operation, I selected as a target an unallocated space on the HDD which is 143GB wide. The position of this unallocated space is roughly 90GB beyond occupied disk space. The selection is accepted by DD but the NEXT box remains grayed out.