Repeated frames on raw video

[daggoo]

Is very useful form me to use crop 3X filming wild fauna.
I use Canon 5DII and raw2dng to extract the frames,
adobe camera raw for adjust levels and adobe media encoder to create the clip.
All goes well BUT sometimes there is an error that make me crazy.
the second frame is repeated ( i.e. file 02-04-06-08.....) so i can't
do the clip.
Is this a known error? What can i do?
Thanks in advance.