Yup so I click on the ground to move, and my character teleports randomly toward it, while the walking animation plays sometimes, sometimes he walks in place for over 2 seconds. Restarting my computer did not help, and it only happens in multiplayer

Some more details would be nice?

What game? Persistent world or just group campaign? Does it happen only in specific modules? Etc.

Sounds like lag, though.

I play NWN2 OC now and sometimes I have the same problem.
I click somewhere and my char teleports in that direction and the walking animation is shown while the char stays at this place. When I click on the ground again he teleports to the place where he should be if he was walking to the first place I have clicked and moves normally from there.

This sounds like the lag-monster. It's one of the top character-killers in NWN.

I'm not sure how you ruled out lag, but I've seen the same thing many times in NWN1 (haven't played much mp in NWN2) and it's caused by lag. It usually presents itself when you join a server with a long ping time or a lot of people on it. But sometimes it just happens (perhaps the server's computer is busy doing something).

This happens frequently even in singleplayer in NWN2. I find that the problem is worst when using keyboard controls; if you use the mouse to point-and-click to move it becomes much less of an issue.

How they managed to get the game to lag in singleplayer is beyond me.

I think in those cases, it's a function of the real-time-ness conflicting with the turn-based-ness of the game, though I could be wrong.

Hopefully, this upcoming DnD game will blow us away (though I have my reservations).