Hey I found a possible bug with line(...) and P3D
Not shure if this appears on every system, thats why I wanted to ask first before putting it in the bug database.
The following code produces the following output on my machine:

http://img703.imageshack.us/i/bugq.gif/

It's very reproducable, evry run the same lines are not drawn.

Problem occurs only in P3D mode.

1. void setup()
   {
     size(600, 100, P3D);
     background(0);
   }
   
   void draw()
   {
     for(int i=0; i<600;i++)
     {
         stroke(255);
         line(i,0,i,99);
     }
   }