Just a question, was your PC rebooting or just shutting down?
Just a question, was your PC rebooting or just shutting down?
No one else seemed to pick up on this but I think your RAM isn't running in dual channel mode and is performing worse then it should. In most boards dual channel slots are the first and third or second and fourth, essentially meaning you shouldn't have the sticks next to each other. This most likely isn't related to your problem but I'd at least try using dual channel slots if you don't wanna gimp yourself. The correct slots are usually color coded too (having the sticks in same color slots is the right way).
I also don't think your problem was ever about RAM slots. Most likely the dusting and/or reconnecting was what fixed it. Or your power supply was just unstable.