On my end, the audio, not the video is moving. Yes, I've placed the marker at the end prior to adding the effects. The video remains stationary, but the audio moves 15 frames left.
As far as preferences, I had the default effect length set to 1 second, but it has also produced the same result when it was set to 1/2 second.
I'm using insertion mode. I'm not sure what other settings might be relevant here.
Bear in mind, these project lengths are over an hour, sometimes two hours, with lots of cuts between two cameras (and therefore many fades). I don't know if the length of the project or the number of fades has an impact, but I thought I should point that out.
I should probably grab a screen shot sometime of a project that is impacted like this. But in the meantime, here's a crude representation of my timeline, using two tracks of audio, and one track of video consisting of alternating shots between two cameras.
V = Cam 1
v = Cam 2
A = Audio
- = no audio at that point on the track:
0:00. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:14:00:00
Ok, assume that the right side of that timeline above is aligned perfectly for all three tracks (ASCII isn't letting me do it)
Notice the audio gap on the first track of audio. In this instance, when I add fades to my video track, the second portion of the track 1 audio will shift 15 frames left. The first portion of the audio track (and the second audio track) will not be affected. The video track will also not shift.
I hope that helps a bit visually.