Hi, thanks for responding, unfortunately that's not it. :( The widget sidebar under Appearance > Widgets has two widgets there, a slideshow and a Facebook Like box, that's all. On all the non-Woocommerce pages it looks perfect, but on the Woocommerce pages (Shop, My Account, Products etc), those two widget areas have been pushed down and a list of all the pages, both the Woocommerce and the main site pages all mixed up together, is in a list above the widget areas. The links are active but they look awful, they're not in a white sidebar like the widgets are, they're just up against the background image.
In addition, I've found a second problem with Woocommerce: in the Shop > My products section, rather than listing grouped products and showing the individual products in each group only when you click on their group, it's showing every product all jumbled up together. To my mind, it makes no sense since one is a parent category of all the others. I would like it to just show the grouped products on this page and that you have to click on the grouped product to see all the various products in that group. Is there any way to achieve this?