why the drop of 5%, page-35

I think the issue here is similar to that of MMS (if not worse) whereby the profitability and thus the entire business model is dependent upon the generosity of telstra.

So whilst on a normal valuation basis it may appear compelling one must ascribe some sort of risk premium to the valuation to take this into account.

Whilst im not one to quote warren buffet one saying does come to mind (mind you taken in a different context):
I have pledged — to you, the rating agencies and myself – to always run Berkshire with more ample cash. We never want to count on the kindness of strangers in order to meet tomorrow’s obligations. When forced to choose, I will not trade even a night’s sleep for the chance of extra profits.