CS5 sort by "Filename" won't hold

I am using CS6 so this may not be relevant but I am assembling a 12 month sequence of shots from the same location to hopefully show the changes in the seasons, during the 12 months I started out with a D700, in April I bought a D800 and in November I upgraded to a D800E ( my wife has the D800 ) so there is a real mis match between image numbers and dates with overlapping file numbers, I went to sort and selected date created which put the files in date order. I have just looked in Bridge to see if the setting has been retained, on opening the folder they seemed mixed but seconds later they were in the required date order, it just seemed as if Bridge needed a few seconds to remember what my settings were. I am using a rMBP approx 6 months old, I am not sure if that will be of any help but that is my experience 5 minutes ago.