My April application came back for exactly the same reason. I called CIC to ask about the photos (in August). They told me that the date of the photo needs to be under six months by the time CIC receives the application (the time of AOR), and that by October I will be fine. I had taken the original photos in April. So when I applied in August, I assumed that they open the application at least in October (if not later), and I was on the 6-month border. I decided not to risk it and to take new photos. The difference for me is that, I re-applied quite late. My application got returned in July but I applied in late August. If you took your photos in August, and you want to apply now in October, you are safe.