AS grades.

I put the certificated date as the date when i sat the exam...so June 2008.

If you haven't cashed in your As and are continuing put grade pending and completion date as august 2009 and not 20 08 because you didn't finish the exam in 2008.
If you have dropped however, put the subject in the As section and leave a blank space where the grade should be entered and completion date of august 2009 too.