There is a known problem with flickering, pixellated/jagged shadows like on NPC faces around a campfire, but I'm not sure if it is the same problem you are having. I've been fiddling around with my SkyrimPrefs.ini file for the past couple of days with limited success but nothing has quite solved it completely.
I found this mod here http://skyrim.nexusmods.com/downloads/file.php?id=8043#content but I can't really vouch for it, because there is a bare description, nothing in the 7z except for an esp (mod) file, but no description on what it does specifically or how it fixes the problem.
Kinda vauge. I guess the days of decent Readme.txt files from Oblivion and Morrowind mods have not continued for too many Skyrim mods so far...
