I've only experienced this with the POTM server.
Running the Android NWN client, I login as my character, and I cannot move. The game client thinks that I'm currently doing 'something' and I cannot move, other players can hit me, but I don't retaliate, I take damage.
When I log back onto the windows NWN client, I'm still stuck in position and have the same problem, however now I can use the @ commands to force myself to sit down, and then find the nearest seat. After running this command, logging off and back on, I can then stand up and walk around.
It only happens when I switch to logging on with the Android client.