I know that you are not using Gamebryo for Skyrim, but I don't know if the Creation Engine is an offshoot of Gamebryo. If it is, this bug should be brought to your attention, and hopefully fixed for Skyrim:
The engine runs at 64HZ/64FPS but the monitor is at 60HZ. So what the game engine does is drop 4frames per second to sync the engine with the graphics card/monitor this is what causes the frame skipping. Only one other game engine does this and thats the one with Doom 3 and Prey !
This was fixed by the mod Oblivion (and Fallout) Stutter Remover through some clever coding.
See description and more technical details of bug on http://forums.nvidia.com/index.php?showtopic=183427&hl=oblivion&st=0. Also reported on Steam forums http://forums.steampowered.com/forums/showthread.php?t=1525127&page=4.