I don't think it is your system, as I have experienced it also. For me, it seems to happen more often when there is a programmed scenario of NPCs talking to each other and I am not a participant in the conversation, like when I have a vision of ghosts or past events such as during Esme's quest; I happened to be in back of the statue when I clicked on it, and the vision appeared some distance in front of the statue, so I was too far to hear it clearly and some of the conversation was completely missing, perhaps because one speaker was even farther away.
If I recall correctly, I also experienced that problem in the Sun Temple conference room (during my old pre-FS playthroughs which are now dust), where I was frozen in one spot during a dialog but the various speakers (Tealor etc) moved around.