Question:

"ZIP Code" will not accept a UK post code, it says "Please check your ZIP code"

Cause:

When you create an account you have the option of creating either a "US" or "UK" account. The US account will reject a UK post code if you try and enter it into the ZIP field. Try again and ensure you select the UK version.

See: http://www.ebuttonz.com/help/dreamweaver/reg1.htm