I have asked about the class of the SD card and Contour say the class is not a problem
un like if you had a GOPRO which needs to be no lower than class4.
Also is the SD one that they recommend and does the same thing happen
when using the SD card that came with the head cam
Do you have the GPS version? has there seems to be problems with them
I think its due to losing GPS signal but un sure.
Have you checked the battery terminals are clean.
Also has above i found that getting the position you want on the helmet and putting grip fill
under the mount and re attaching and letting it dry before using helps big time.
Have you tried the Contour forums has they have good advice on there.
Try another battery also the old Nokia battery works in them.
Nokia Battery BL-5C 1020 mAh
Good Luck