The OP/ED are often 30fps (TV frame rate), while the actual content is normally 24fps (cinema frame rate).
With 120fps video, most of the frames are null (i.e. not there). If 1 in 4 frames are non-null, you get 30fps, while 1 in 5 gives 24fps.
IOW, 120 "fps" just means a video time-base of 120 "ticks" per second, with each frame lasting either 4 or 5 ticks.
In any case, the raw providers do seem to be getting more computer literate. E.g. they have recently started to understand that WMV isn't the only video format in existence.