Well i'm back.
After a lot of tests, my problem is :
When i enable card spanning for record with 30fps or more (no problems with 24fps), even if i enable 30/50/60fps in the Canon's menu, i get droped frames, but i dont have problem for record, it's only when i check the movie with the MLV Player, or on raw2cdng and of course if i extract my DNG, Resolve show multiple sequences because i get droped frames.
I need to disable card spanning for using 30fps or more.. I dont understand why. I disabled CF Only Buffer too, but no results.
Then i can't really use Card spanning, My cards are : CF Lexar 1066x 16 gb + SD Lexar Extreme 45 mb/s 16 gb.
I tried to install ML on the CF or the SD, it's the same.
And of course both cards are formated in ExFat
Is it an internal problem in my 5D mark III ? I did a big reset of my configurations, upgrade and downgrade the firmware too, it's the same.
ps: sorry if my english isn't clear sometime, i try my best !