I tried out making my swatch last night with my new yarn and the 3.5mm hook. It honestly looked to me like it was working up too big, but when I measured it, it was still 1/2 cm too small !!!
Tried again with a 4mm hook and it came out just about bob-on. I think I must crochet really tight.
I decided that I didn't really like the colour of yarn I had so I've ordered a couple more colours. Its so hard to tell what the colours will turn out like when you can't really see the yarn texture and the colours are dependant on the quality of your monitor.
So in the end I've ordered up one each of numbers 5, 9, 19, 33, 58 & 95. I'd previously got a 48 and 20. The 48 is a little bit "school jumper" and 20 is quite nice but I think it might be a bit dark for the cardigan I am making.
I will always find a use for the various yarns, so I don't feel too guilty about ordering such a selection of colours.