My voucher for the exam is about to expire, what can I do?
Check the voucher conditions on Sun's web page of your country, or the wording on the back of the voucher. It may have words to the effect of:
"You must register for an exam prior to the expiration date printed on this voucher. Voucher expiration dates cannot be extended. Your actual testing appointment may be deferred for up to one year after registration."
So register for the exam before the voucher expires, then contact prometric and defer the exam. You may defer multiple times. Be aware that Prometric and the test centers themselves have requirements as to how much notification must be given before defering an exam. So dont leave it to the last minute.
Please be aware that the FAQ you copied from was from a long time ago - back before Oracle took over from Sun, and from back before they moved away from Prometric. Since neither Sun nor Prometric are involved in the certification process anymore, the situation may have changed. If you find out it has, it would be wonderful if you updated the FAQ.