ohyeah,
certain conditions need to be satisfied for tax purposes for scrip-for-scrip rollover relief. If satisfied then cost base post scrip for scrip is same as first purchased ie april08.
For those interested in light tax legislation reading:
http://www.austlii.edu.au/au/legis/cth/consol_act/itaa1997240/
refer provisions 124-775 to 124-810 under the heading:
Subdivision 124-M--Scrip for scrip roll-over