When I import photos in lightroom, it does not always show them in the correct order in the library module when I have a multiple photos with the same time stamp of when it was taken. It should order them first with the time stamp and then by the file name. Very often when I import a shoot with a high FPS, the time stamps are identical but lightroom may not order them sequentially by filename. Is there any thing I can do to fix that?
Rumor has it that LR does not use the fractions of a second in the timestamps for any purposes including sorting.
Your best bet is to make sure the original file number is included in the file name to assist in the proper sequencing.