Hi Jo
Overall the site looks good, but...
1) I really don't like embedded frames. They're usually not necessary and it makes the actual shopping area (where you view the goods) very small.
2) The font on the images at the top menu appear blurred, probably because of the style and size of the font.
3) I added something to my basket, but when I clicked on Continue or Checkout nothing happened. I'm using Firefox. It worked on IE.
4) I also found it a little irritating that the mouse pointer didn't change to a hand as normal when hovering over the Add or More Info buttons. Again this is using Firefox - in IE it was fine.
5) Away from the design, £5 delivery charge is very high. If I were going to buy a box of chocolates for £6, I wouldn't bother once I saw the delivery charge is about the same price as the chocolates.
6) The site says it uses SSL secured pages, however because it is framed, customers won't see that. You'll get a lot of dropped carts as a result.
7) Another Firefox/IE quirk - in IE the site is centered, in Firefox it's aligned left.
Hope that helps!
Gary