The number '0' is being prefilled in my Virtuemart forms?

[reders]

Hi,

I'm having a strange problem whereby the form fields are being prefilled with '0' when you try to edit the 'bill to' or 'ship to' forms.

Could someone please explain how I would correct this?

The URL is: http://www.chalet-interiors.com/component/virtuemart/user/editaddresscartBT?Itemid=0

Many thanks.