Magento URL string problems

I thought I'd come back to this prob a little later, and now is a good time.

Basically, the URL's for the footer links all work fine if you click them from the homepage or product pages. It just goes directly there following the URL I specified for the page. For example: MYSITE/Terms_and_conditions

However, there's a really annoying issue where if anyone is on any section of the checkout (so either MYSITE/Checkout/Cart or MYSITE/Checkout/onepage) and then attempts to go to any of the footer links, it leads to a 404 page not found error.

The reason is because instead of replacing the checkout URL, it just adds the footer link URL onto the end, so I end up with something like this:

MYSITE/Checkout/Cart/Terms_and_conditions

or

MYSITE/Checkout/Cart/Onepage/FAQ

Obviously these URL's don't exist, which is why it's giving the 404 error.

The 'Checkout' pages are not the only place doing this, it also happens if you try to navigate to a footer link from the 'contacts' page (for sending an email.)

So does anyone know how to stop the URL's from stacking up when navigating to the footer links when on these pages?

Thanks once again for your help folks!