--- pDraw.class.php.orig   2011-12-27 09:27:44.011810124 -0700
+++ pDraw.class.php.fixed   2011-12-27 10:01:56.563830357 -0700
@@ -3852,62 +3852,83 @@
      $PosArrayB = $this->scaleComputeY($SerieBData,array("AxisID"=>$AxisID));
      if ( count($PosArrayA) != count($PosArrayB) ) { return(0); }

-     if ( $Data["Orientation"] == SCALE_POS_LEFTRIGHT )
-      {
-       if ( $XDivs == 0 ) { $XStep = ($this->GraphAreaX2-$this->GraphAreaX1)/4; } else { $XStep = ($this->GraphAreaX2-$this->GraphAreaX1-$XMargin*2)/$XDivs; }
-       $X = $this->GraphAreaX1 + $XMargin; $LastX = NULL; $LastY = NULL;
-
-       $LastX = NULL; $LastY1 = NULL; $LastY2 = NULL;
-       $BoundsA = ""; $BoundsB = "";
-       foreach($PosArrayA as $Key => $Y1)
-        {
-         $Y2 = $PosArrayB[$Key];
-
-         $BoundsA[] = $X; $BoundsA[] = $Y1;
-         $BoundsB[] = $X; $BoundsB[] = $Y2;
-
-         $LastX = $X;
-         $LastY1 = $Y1; $LastY2 = $Y2;
-
-         $X = $X + $XStep;
-        }
-       $Bounds = array_merge($BoundsA,$this->reversePlots($BoundsB));
-       $this->drawPolygonChart($Bounds,array("R"=>$AreaR,"G"=>$AreaG,"B"=>$AreaB,"Alpha"=>$AreaAlpha));
-
-       for($i=0;$i<=count($BoundsA)-4;$i=$i+2)
-        {
-         $this->drawLine($BoundsA[$i],$BoundsA[$i+1],$BoundsA[$i+2],$BoundsA[$i+3],array("R"=>$LineR,"G"=>$LineG,"B"=>$LineB,"Alpha"=>$LineAlpha,"Ticks"=>$LineTicks));
-         $this->drawLine($BoundsB[$i],$BoundsB[$i+1],$BoundsB[$i+2],$BoundsB[$i+3],array("R"=>$LineR,"G"=>$LineG,"B"=>$LineB,"Alpha"=>$LineAlpha,"Ticks"=>$LineTicks));
-        }
-      }
-     else
-      {
-       if ( $XDivs == 0 ) { $YStep = ($this->GraphAreaY2-$this->GraphAreaY1)/4; } else { $YStep = ($this->GraphAreaY2-$this->GraphAreaY1-$XMargin*2)/$XDivs; }
-       $Y = $this->GraphAreaY1 + $XMargin; $LastX = NULL; $LastY = NULL;
-
-       $LastY = NULL; $LastX1 = NULL; $LastX2 = NULL;
-       $BoundsA = ""; $BoundsB = "";
-       foreach($PosArrayA as $Key => $X1)
-        {
-         $X2 = $PosArrayB[$Key];
-
-         $BoundsA[] = $X1; $BoundsA[] = $Y;
-         $BoundsB[] = $X2; $BoundsB[] = $Y;
-
-         $LastY = $Y;
-         $LastX1 = $X1; $LastX2 = $X2;
-
-         $Y = $Y + $YStep;
-        }
-       $Bounds = array_merge($BoundsA,$this->reversePlots($BoundsB));
-       $this->drawPolygonChart($Bounds,array("R"=>$AreaR,"G"=>$AreaG,"B"=>$AreaB,"Alpha"=>$AreaAlpha));
-
-       for($i=0;$i<=count($BoundsA)-4;$i=$i+2)
-        {
-         $this->drawLine($BoundsA[$i],$BoundsA[$i+1],$BoundsA[$i+2],$BoundsA[$i+3],array("R"=>$LineR,"G"=>$LineG,"B"=>$LineB,"Alpha"=>$LineAlpha,"Ticks"=>$LineTicks));
-         $this->drawLine($BoundsB[$i],$BoundsB[$i+1],$BoundsB[$i+2],$BoundsB[$i+3],array("R"=>$LineR,"G"=>$LineG,"B"=>$LineB,"Alpha"=>$LineAlpha,"Ticks"=>$LineTicks));
-        }
-      }
+     $LastX = NULL; $LastY1 = NULL; $LastY2 = NULL;
+     $LastY = NULL; $LastX1 = NULL; $LastX2 = NULL;
+     $X = NULL; $Y = NULL;
+
+     if ( $XDivs == 0 ) { $XStep = ($this->GraphAreaX2-$this->GraphAreaX1)/4; } else { $XStep = ($this->GraphAreaX2-$this->GraphAreaX1-$XMargin*2)/$XDivs; }
+     $X = $this->GraphAreaX1 + $XMargin;
+     if ( $XDivs == 0 ) { $YStep = ($this->GraphAreaY2-$this->GraphAreaY1)/4; } else { $YStep = ($this->GraphAreaY2-$this->GraphAreaY1-$XMargin*2)/$XDivs; }
+     $Y = $this->GraphAreaY1 + $XMargin;
+
+     do
+     {
+    $BoundsA = array(); $BoundsB = array();
+    $keys = array_keys($PosArrayA);
+
+    if ( $Data["Orientation"] == SCALE_POS_LEFTRIGHT )
+     {
+      foreach($keys as $Key)
+       {
+        $Y1 = $PosArrayA[$Key];
+        $Y2 = $PosArrayB[$Key];
+
+        unset($PosArrayB[$Key]);
+        unset($PosArrayA[$Key]);
+
+        if($Y1 != VOID && $Y1 != VOID)
+        {
+       $BoundsA[] = $X; $BoundsA[] = $Y1;
+       $BoundsB[] = $X; $BoundsB[] = $Y2;
+        }
+
+        $LastX = $X;
+        $LastY1 = $Y1; $LastY2 = $Y2;
+
+        $X = $X + $XStep;
+
+        if($Y1 == VOID || $Y1 == VOID)
+       break;
+       }
+     }
+    else
+     {
+      foreach($keys as $Key)
+       {
+        $X1 = $PosArrayA[$Key];
+        $X2 = $PosArrayB[$Key];
+
+        unset($PosArrayB[$Key]);
+        unset($PosArrayA[$Key]);
+
+        if($X1 != VOID && $X1 != VOID)
+        {
+       $BoundsA[] = $X1; $BoundsA[] = $Y;
+       $BoundsB[] = $X2; $BoundsB[] = $Y;
+        }
+
+        $LastY = $Y;
+        $LastX1 = $X1; $LastX2 = $X2;
+
+        $Y = $Y + $YStep;
+
+         if($X1 == VOID || $X1 == VOID)
+       break;
+       }
+     }
+
+     if(count($BoundsA) > 0)
+     {
+      $Bounds = array_merge($BoundsA,$this->reversePlots($BoundsB));
+      $this->drawPolygonChart($Bounds,array("R"=>$AreaR,"G"=>$AreaG,"B"=>$AreaB,"Alpha"=>$AreaAlpha));
+
+      for($i=0;$i<=count($BoundsA)-4;$i=$i+2)
+      {
+        $this->drawLine($BoundsA[$i],$BoundsA[$i+1],$BoundsA[$i+2],$BoundsA[$i+3],array("R"=>$LineR,"G"=>$LineG,"B"=>$LineB,"Alpha"=>$LineAlpha,"Ticks"=>$LineTicks));
+        $this->drawLine($BoundsB[$i],$BoundsB[$i+1],$BoundsB[$i+2],$BoundsB[$i+3],array("R"=>$LineR,"G"=>$LineG,"B"=>$LineB,"Alpha"=>$LineAlpha,"Ticks"=>$LineTicks));
+      }
+     }
+     } while(count($PosArrayA) > 0);
     }

    /* Draw a step chart */
@@ -6190,4 +6211,4 @@
     }

   }
-?>
\ No newline at end of file
+?>

if($Y1 != VOID && $Y1 != VOID)

if($X1 != VOID && $X1 != VOID)