Currently Being ModeratedFeb 14, 2013 7:44 AM (in response to Nick Howard)
I have sorted this, but randomly. I restarted a couple of times and managed to erase the disk. But it only appeare4d greyed-out in the finder. I gave it a single partition, and then erased that, and, lo and behold, I had a disk on my desktop. Dunno how it worked or whether it will continue to do so, but fingers crossed...