From a 3d sketch I can produce an applet without problems and when i call the index.html the browser displays it properly.
The problem is that if i call it a second time it results in a black screen.
I have tested it on various computers and with different browsers.
Then, if i close the browser and again call index.html, it works fine but again also only once.
Is this a known problem?

I'm using version 2.06a on WinXP with a Geforce GT9600.

Here is a sample sketch:

// 3D Array of objects

import peasy.*;
PeasyCam cam;

GridObject[][][] cellModel;

// Number of columns and rows in the grid
int cols = 4;
int rows = 4;
int staples = 4;

float rotAngle = 0.0;
float angleChange =  0.08;
float angleLimit = 64.0;
float percOpaque = 0.64;
int delta = 0;


long[][][] xyzPos;

void setup() {
  size(680, 400, P3D);
  //hint(DISABLE_DEPTH_SORT);
  //translate(cols/2*100, rows/2*100, staples/2*100);
  //translate(-cols*100, -rows*100, -staples*100);
 
  cam = new PeasyCam(this, 640);
  cam.setMinimumDistance(64);
  cam.setMaximumDistance(1024);

  xyzPos = new long[cols][rows][staples];

  cellModel = new GridObject[cols][rows][staples];
  for (int i = 0; i < cols; i++) {
    for (int j = 0; j < rows; j++) {
      for (int k = 0; k < rows; k++) {
        if(random(1)<percOpaque) {
        // Initialize each object
        //cellModel[i][j][k] = new Grid(i*100+50, j*100+50, k*100+50);
        cellModel[i][j][k] = new GridObject(i*100-(cols-1)*50, j*100-(rows-1)*50, k*100-(staples-1)*50);
        xyzPos[i][j][k] = 1;
        } else {
        cellModel[i][j][k] = new GridObject(i*100-(cols-1)*50, j*100-(rows-1)*50, k*100-(staples-1)*50);       
      }
      }
    }
  }
}

void draw() {
  background(0);
//  rect(0, 0, width, height);
//  rect(-width/2, -height/2, width, height);

    //set up different colored lights
  pointLight(51, 102, 255, 500, 500, 640);
  pointLight(200, 40, 60, -500, -500, -800);
  pointLight(255, 255, 255, -500, 500, -100);
  pointLight(255, 255, 255, 500, -500, -100);

  //raise overall light in the scene
  ambientLight(127, 127, 127);
 
    if(rotAngle < angleLimit){
    rotAngle += angleChange;
    rotateX(radians(rotAngle*2));
    rotateY(radians(rotAngle*8));
    rotateZ(radians(rotAngle*4));
    angleChange = angleChange*cos(radians(delta/8));
    delta = delta + 1;
//    angleChange = angleChange*0.9905;
    }else {
    rotateX(radians(angleLimit));
    rotateY(radians(angleLimit));
   }


  //translate(-cols/2*100, -rows/2*100, -staples/2*100);
//  rotateX(radians(64));
//  rotateZ(radians(32));
  // The counter variables i and j are also the column and row numbers and
  // are used as arguments to the constructor for each object in the grid. 
  for (int i = 0; i < cols; i++) {
    for (int j = 0; j < rows; j++) {
      for (int k = 0; k < rows; k++) {
       if (xyzPos[i][j][k] == 1) {
        // Oscillate and display each object
        cellModel[i][j][k].run();
       } else {
         cellModel[i][j][k].display_fillcubes();
//         fill(255, 0, 0);
//         box(64);
        
        //println(cellModel[i][j][k]);
        //      grid[i][j].oscillate();
        //      grid[i][j].display();
      }
      }
    }
  }
}

with:

// A Grid object
class GridObject {
  // A cell object knows about its location in the grid as well as its size with the variables x,y,w,h.
  float x, y, z;   // x,y location
  float w, h;   // width and height
  float angle; // angle for oscillating brightness
  float z_box;
  int colorshift = (int)random(-32, 32);
  int sizeshift = (int)random(-16, 32);
  int translationshift = (int)random(-16, 16);
 

  // Grid Constructor
  GridObject(float tempX, float tempY, float tempZ) {
    x = tempX;
    y = tempY;
    z = tempZ;
//    angle = tempAngle;
//    z_box = tempZ_box;
  }

  void run() {
//    oscillate();
    display();
  }

  // Oscillation means increase angle
/*  void oscillate() {
    angle += 0.032;
    delta_z += 0.00032;
  }*/

  void display() {
    noStroke();
    //    stroke(255);

    pushMatrix();
//    translate(x, y, z);
    translate(x+translationshift, y+translationshift, z+translationshift);
    //  Color calculated using sine wave
//    fill(216+127*sin(angle), 216+127*sin(angle), 8+127*sin(angle));
    fill(32+colorshift, 32+colorshift, 122+colorshift);
//    box(64+sizeshift, 64+sizeshift, 64+sizeshift);
    box(64);
//    box(20, 20, 16+8*cos((10-z_box)-delta_z));
    popMatrix();
  }

  void display_fillcubes() {
    noStroke();
    //    stroke(255);

    pushMatrix();
    translate(x, y, z);
//    translate(x+translationshift, y+translationshift, z+translationshift);
    fill(191, 64, 0, 127);
    box(64+sizeshift, 64+sizeshift, 64+sizeshift);
//    box(64);
    popMatrix();
  }
 
}