Problem is not changing shutter for the video, its the stills. before setting video.
I have the same problem, After watching a video on setting up the 7D for video. they start off by setting the camera to M then iso to 160 aperture ( lens allowing to 2.8 But the shutter speed gets set to 50th sec. i remember I had this , Once , but cannot get into it, I can select 45th 60th But not 50th. Why is this ?