Ps: Roel, this is just for info so you can wipe the post if you want, but I just wanted to mention this:
I have been in communication with Oracle quite a bit this week, because in the past you could upload the assignment and then do the essay exam thereafter, but the process has changed.
I received emails from both the email addresses : email@example.com and developer-submit_US@oracle.com; and herewith one of the replies:
Please be sure you have completed your essay exam (310-027) before sending us your completed assignment and include your Prometric test ID with your assignment submission.
I'm fine with this, but I just thought there are others that don't know this. For instance, I have to send my assignment through by the 30th of April and if I didn't know that I had to do my essay exam before sending it through, I would not even have gone onto the Prometric site and booked the exam - because my exam voucher only expires on the 31st of May.