Hi Karthik,
I also had a delay of a few days.
Actually I had a worse problem than that. I purchased the
SCJP 1.2 -> 1.4 upgrade voucher at the same time as I purchased the SCJD assignment, and someone blocked my SCJD voucher because they thought I was not an SCJP :roll:
Anyway, once I had Sun agreeing that I was an SCJP, they sold me the voucher. I think I waited 3 days after the assignment was approved before I received the email from Prometric giving me access.
End result: you may want to wait a few more days.
Regards, Andrew