After installing CUDA 5.5 I got a nVidia driver 325.15 that dates to 05.08.2013 installed in my Ubuntu machine. I now checked the nVidia driver download page and found an update driver 319.49 that dates to 20.08.2013 and therefore the confusion. The new driver seems older by the numbering, is it? is the 319.49 a valid upgrade or not?
I have two GTX Titans.