Well I just ran into problem because Sun (Netherlands) told me that I only needed to submit the assignment and have to reserve for an exam before the voucher expires. This is NOT correct, this is very old info!
Prometric told me to submit AND do the
test before the voucher exipers. They also told me that if you fail you can bye a new voucher and simply do the test again with the same/identical assignemt.
Do others think this info is correct? Anyways, if in doubt, please call you local testing organisation and/or Sun.