How to make Black Glutinous Rice sticky?

I’ve been to a Cooking Class in Thailand and learned how to do many yummy Thai dishes. One of them was Mango with Sticky Rice, but with black rice.

My problem is that somehow my rice is not sticky at all although I’m doing what is written in my little recipe paper that I got from the cooking class.

I show you two pictures (first time and second time):

The first time, with little coconut sauce:

The second time, with a bit too much coconut sauce:

So now to the cooking instructions.

I’ve got this brand for the rice:

And according to my recipe paper, I need to soak 2 cups of rice in 4 cups of water at least 8 hours. (I usually do about only 8-10 hours).
And then I need to steam the rice in a rice steamer for 20-30 minutes. I don’t have this so I’m using the ikea steel steamer:

_{(source: ikea.com)}

And I’m using a normal pot with water to steam it with the lid closed so no steam comes out.

The result is that the rice is "dry" and not really sticky at all. The last time I did it we had so much of the rice left, that we thought we could do sushi with it. But it was impossible since it does not stick at all…

What am I doing wrong?