You could try changing http://cs.elderscrolls.com/constwiki/index.php/FPowerAttackDelay in the CS to increase the time it takes before a power attack is executed.
EDIT: Although it seems like your mouse is damaged and the button gets stuck after pushing it. So maybe buying a new mouse would be a better solution in the long run.
Changing the delay time for power attacks worked. And no, my mouse isn't "damaged", the game seems to lag during rather important combat sequences.
This can also happen if your framerate is low-ish. (Doesn't have to be extremely low, just under 20-ish FPS. It's a stupid quirk of the input handler.) I'm pretty sure Oblivion Stutter Remover includes a tweak to fix it, if that's the problem.
Yeah, my FPS WAS, in fact, low at certain points. Found out just last week that the most major reason for it was the game's light refraction effect with Chameleon. :pinch: :wallbash:
On that note, is there something similar to the "Morrowind FPS Optimizer" that I can use for this game?