So there I am, the sword out hitting the mouse buttons just for Geralt to do nothing. Not block, not hit just move around. It happens more often the longer I'm playing the game. It did not happen from the start. I was lvl 20something when it happend the first time.

Just now I read that still is a problem in Witcher 2 so I guess the chance of this being fixed is next to zero?

Restarting the game helps but then I found out that putting the weapon away and drawing it again helps too. It is still very annoying that it even happens.