Adjusting Vario Cleat - North 5th Element Bar

Hi guys, Apologies if this has been asked before.

I've just got a 2011 North Rebel and I'm trying to adjust the the length of the depower stroke by moving the vario cleat (my arms are too short for the current setting!),.

Looking in the manual, this seems trivial: http://www.northkites.com/uploads/tx_vipmediadownload/nkb_mnl11_bar_en_128170689656.pdf

And also from this video:

But this is just not working for me!

I've pulled out the tab for the cleat, pulled throw the depower rope and put it back. But now I have a huge amount of slack between the cleat and the bar. This is surely not right. See the pictures of what I am left with.

Am I doing something wrong? The only solution seems to be for the depower rope to move through the "Roto head" to even out the slack. My rope doesn't move...should it?

I really can't see what I am doing wrong. As I say, it looks so simple from that video, but for the life of me I can't make this work!

Any help would be much appreciated.

Photos of what I am trying to do :)

The bar as it is:



The cleat unmoved:



The cleat with the tab pulled:



All the slack I am left with:

I'm doing a free beginners clinic at 5pm monday at Point Walter for our customers, pop down then and I will do it for you.