The simple method of downloading it to your PC will not drop frames (assuming its PC your using?) if you right click and check details it should show the original 60fps with the resolution information.
Are you grabbing the raw data off a memory device or downloading through a program? If the latter, try copying the raw data in a straight folder copy. Now the viewing and editing process you use after that may drop frames, but you're saying the file is dropping to 30 frames by simply downloading it?
Where are you getting the information on the downloaded files frame rate?
Edit-sorry just re-read your post above that answers some of these questions. So its showing 30fps only on your properties of the raw SD card file when inserted without even downloadign to your PC? weird.
Tried it on a different PC?
Last edited by NZRide; 01-19-2014 at 02:14 PM.