It happens consistently, whenever a NPC says one of their lines it's like they miss a word. There is a pause of silence where the word should be, they just don't say it.
Like, "I was an adventurer like you, then I took an ....... in the knee." The pause is the length the word should be.
I also have a second issue, unrelated (I think). The strong box has no sound fx when it opens or closes, but all the other containers do. Is the open/close sound defined in the NIF file? I've looked at the various containers in the CK, and none of them have the open/close sounds defined. If I remember correctly, the sound for some objects were specified in the NIF file in Fallout3.
My first thought is it has something to do with software vs. hardware acceleration, but I don't see a setting to disable/enable acceleration in either the skyrim.ini file, or skyrimprefs.ini. file.