Hi,
I realise this thread is old now, but i have also recently noticed that my Aero stopped working, with no issues being detected.
I just wanted to post this as it may help others. After a bit of digging around, i noticed that for some reason, my "colour depth" within the display settings had been reduced to 16 bit. Not a clue how, but after changing back to "Highest - 32 bit" Aero came back.
There are obviously lots of different reasons why Aero may stop working, as i found by googling, but hopefully this may help others if their display settings have changed.
Thanks
Andrew Perry