My CTO630 now thinks it's a CTO900 ??

[Daftdog]

Setting up the CTO630 this afternoon I was paging through the menus (which by the way seem to be a few menus short of a full bunch, but we won't go there yet!) and fiddling as you do, and I've somehow managed to make the machine think that it's a CTO900. I've fiddled and fiddled with it, and I can't now make it realise that it's actually a CTO630.

Any ideas?