I've now had a good look round to make sure all the areas that should be secure are, and all's well.
A new problem has arisen in that once an item has been added to the cart and the checkout process started, I can click on the next step and the page simply refreshes back to where I started instead of following on to confirm delivery address, etc. This only occurs when ssl is enabled in admin.
When it's disabled I can go through the checkout process no problem but obviously the security isn't there which isn't ideal

Any ideas as to why the page would refresh when trying to checkout when SSL is enabled in admin????
It's currently disabled as Sunday nights are one of our busiest.
address is: beaumont-furniture.co.uk