I was able to buy the voucher for Java 2 SCEA by calling SUN on their contact no. Though it wasnot smooth as not all of the team member sin the training/certification dept knew about the fact that vouchers could be bought over the phone even after 29 Feb.
I could get through this and buy it after making 3 calls. Two of them were eager to inquire about it and one of them just reluctant and hanged down .
However I am happy I was able to buy and would say that all those ewho aspire to take this exam please call SUN . I am not sure how long they would continue to do this. I bought this on last Friday and received the email for downloading assignment just yesterday.
The lady at SUN said they would continue for a couple of days more.
So check it out with SUN. Good Luck!