Hey Dave- Congrat's on the fourth kyu!
Tsubaki sensei is the head instructor of my dojo. He's been all over the place this summer, and we look forward to him returning here in a few weeks.
I don't know if this will help, but someone recently has told me that when you test for a rank, you are at the bottom wrung of the ladder of that rank, so to speak. I've seen lots of people do not so hot on stuff that they should know, I think probably because they are concentrating too much on learning the new material. But a test should be a learning experience, and in your case it looks like it has been. So by those standards, even though the fifth kyu stuff didnt' shine like you would have liked it to it was a good test.
I think I may need to follow my own advice, because testing at our dojo is coming up around the corner. Congratulations again.