love changing RAM on an iMac
While my problem may likely be related with having Mavericks installed, I decided to double my RAM from 8GB to 16GB. I love changing RAM on an imac because it's just so easy... Unlike the first time I changed RAM on the early model mac minis - which was scary as heck!
No problems and straight forward. A simple twist of 3 screws and I was back in business.
If you ever look to try a repair guide, this is the one to try.