If you're having problems adding or subtracting items from your basket we would advise you hit the + or - button or hit the x button. This will then remove each item individually.
If this does not work, we would advise that you delete your temporary internet files. To do this in Internet Explorer on Windows simply select the tools option from your web browser. Then select internet options, click the button 'Delete Files' and press 'OK'. Also click on 'Settings' button next to the 'Delete Files' button and make sure 'Every visit to the page' is selected.