sudden increase in volume, page-23

You are probably correct in assuming institutions are involved due to the high volumes.
At this point in time, what would be the reasons / scenarios to manipulate the SP down?
Other than the obvious reason to buy more shares at the lowest possible price, if the underwriters of the CR wanted to get their hands on as many shares as possible through maximising their underwriting obligations (take up of unsubscribed shares) then it would be in their interests for the SP to be below the $1.10 CR price in the period prior to the subcription deadline 13 August 2012.

I suppose everyone needs to be aware of the historical manipulation / high SP volatility which provides differing opportunities for traders V investors.

Investors should not be concerned by these short term fluctuations as the fundamentals will rule the SP eventually. I certainly intend to take up my 125% entitlement