I have had the dread files missing on the SCHC card (the card was OK) some footage was there but footage shot earlier in the day was not there any more and only noticed when I got home. the camera gave no indication of any problem and all the indicators were showing the correct readings, TC & elapsed, remaining.
After a long search of many useless programs claiming to find and recover mp4 files, I found the one below found the LOST folders and files and managed extract them all. My edit software would not see & import (Sony Vegas) the correct file structure with the files, but I just dragged the mp4 files into the correct folder. Everything seems to be up and running now.

The free one also saw the LOST file structure but would not recovery the mp4 file for me, it managed mts and other documents etc. OK

(free trial with option to recover one file a day to check it works)
Recover Files Deleted from Memory Cards (http://www.recovermemorycards.com/)
Handy Recovery - Recover files accidentally deleted on MS Windows. Partition Recovery. (http://www.handyrecovery.com/)

Free but does not always recover correctly)
PC Inspector - kostenlose Software für die Datenrettung von CONVAR - Die Datenretter. (http://www.pcinspector.de)

Hi Zulqar,

Many thanks for posting, luckily I have not had any problems as yet but I will keep this posting in mind should !!!!!

Mick