Having looked around here I couldn't find an answer to my question.
I am having trouble selecting an individual instance in a population group, despite having changed the spacing distance to 50. It seems that no matter where on the instance I click I can not get its bounding box to turn yellow and get access to its origin handles to move individual instances (In this case trees) so that they maybe placed in the places I want them to be.
Regards to you.
Cyber-Angel