PieEater

NP - I believed that you had taken my comments on board I just wasn't too happy with some advice given to you and potentially others that may stumble across this thread in the future and wanted to qualify where I was coming from. 
 
I have just done a quick 15 minute flight any my temps are similar to yours - 61 / 64 / 69 / 65 - although we're not comparing apples with apples when it comes to CPU cooling solutions (closed lop vs air) I don't recon you have anything to worry about as long as your cooler isn't struggling to keep things under control. 

When you re-installed the 310.90 drivers did you completely uninstall the 314.07 and use something like Driver Sweeper to make sure the new drivers were completely eliminated? If not it would probably be worth doing as if the new drivers did introduce the problem a normal uninstall/reinstall may not neccesarily get rid of whatever it was that was causing the issue. You can get Driver Sweeper here - http://www.guru3d.com/content_page/guru3d_driver_sweeper.html

The Rosewill one looks fine, plenty of reviews online they all seem to suggest that it does the job and is worth considering if you're on a budget.