Help with depreciation in cash flow statement.

hey all.
Here comes another time when we have to start helping each other.
In the June 2011 question 3. statement of cash flow.I need some explanation as to the treatment of depreciation value of 640.
Normally I know depreciation is added back to pbt in the operating section of cash flow statement. After solving the question, it could not balance,so i refer to the answer only to see that the depreciation value was added back to ppe in the investing section to get the cash spend on investing activities. Is this not double counting.
plse need help with clarification for me to understand it.

Thks to all the wonderful pple on the forum.