Anybody at all? Would be a great help     

Have you tried to check if mouse is inside the canvas? Like if (mouseX > 0 && mouseX < width)... Also there is 

Thanks for the suggestions.

As far as I have found out, pauseOnBlur is for focus on the entire program/tab. The mouse leaving the canvas doesn't do anything for this yet. I haven't been succesful with an if-construction like that either.
The problem is that when a button is pressed, the mouse is moved out of the canvas, unpressed, and moves back in, Processing still believes the button is pressed. I'm not sure if I can unpress it somehow.

And you were very right about the smooth and noStroke(), changed that.

Hummm. no good? Another shot:

//Run this at the beginning of draw() and you'll get coordinates outside of the frame even when the mouse isn't clicked.
//Source Code

/**
clickedmousepos taken from http://wiki.processing.org/index.php/Mouse_events_outside_window
@author Yonas Sandbk
*/

void setMouseXY()
{
  if(mouseX>=0 && mouseX<width && mouseY>=0 && mouseY<height) return;
  Point mouse, winloc;
  mouse = MouseInfo.getPointerInfo().getLocation();
  winloc = frame.getLocation();
  if(!frame.isUndecorated()){
    winloc.x += 3;
    winloc.y += 29;
  }
  mouseX = mouse.x-winloc.x;
  mouseY = mouse.y-winloc.y;
}

The question was actually about the JavaScript mode, but thanks for sharing anyway (it can be useful to somebody else).