Oiks, I'm talking to myself!
As a little update, I tried running Nero up with no disk in the drive, and it appeared to be prepared to let me select 16X...
Does this mean it maybe just doesn't recognise the actual cd media as being 16X capable ? I've ordered some new cd's (Memorex) but they'll take a few days to arrive, so I won't be able to 'test' this theory for a while yet.
Fingers crossed
Rob.