This is my first post here. I really have no where else to turn for help. I currently own a 5DM4, 5DM3, AND 6D..I never had a problem with my 5DM3 or 6D until a couple months ago. I do a lot of time lapse work and have recently noticed that my video is shaky, jerky and appears to be missing frames. For example, yesterday, I set the 5DM3 up with an external intervalometer (like usual). My settings were f8, iso 800, shutter speed at 2000. I set the interval for 4 seconds to give the camera ample time to write to the card buffer, of which, I used Lexor 32 gig, 160mbs 1066x card shot in jpeg. After getting home and loading it into my pc, it is so jittery and shaky that its hard to follow. I just had canon replace the shutter and mirror. All to no avail. Is it possible I may have a bad 3 pin jack on the 5DM3? I appreciate anyone's input and assistance. Mark