FULL PRODUCT VERSION :
1.6.0_10-rc2

ADDITIONAL OS VERSION INFORMATION :
Windows XP SP3

EXTRA RELEVANT SYSTEM CONFIGURATION :
IE 7 or Firefox 3, using plugin2

A DESCRIPTION OF THE PROBLEM :
Since 1.6.0_10, Applet.getImage() returns a sun.plugin.util.ToolkitImageWrapper.
ImageObserver.imageUpdate still sends a sun.awt.image.ToolkitImage.

It is then impossible under 1.6.0-10-rc2 to know which image returned by Applet.getImage() is now ready.


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Using the following applet (taken from http://forums.java.net/jive/thread.jspa?messageID=297683&tstart=0).
Add 2 JPEG images in the codebase called image1.jpg and image2.jpg.
Point your browser to the applet codebase.



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The applet should return something along the lines of:

Preparing image1.jpg (sun.awt.image.ToolkitImage@1820dda)
Preparing image2.jpg (sun.awt.image.ToolkitImage@112f614)
image2.jpg is ready
image1.jpg is ready

(this output is taken from 1.6.0_07)
ACTUAL -
Preparing image1.jpg (sun.plugin.util.ToolkitImageWrapper@176c74b)
Preparing image2.jpg (sun.plugin.util.ToolkitImageWrapper@1ee3914)
sun.awt.image.ToolkitImage@1f14ceb is ready but it does not match any of the prepared images
sun.awt.image.ToolkitImage@f0eed6 is ready but it does not match any of the prepared images



REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
// ---------------------------------------------------------------------
import java.applet.*;
import java.awt.*;
import java.awt.image.*;

public class Java6Bug extends Applet implements ImageObserver
{
  Image image1, image2;
  String image1Name = "image1.jpg";
  String image2Name = "image2.jpg";

  public void init()
  {
    image1 = getImage(getCodeBase(), image1Name);
    image2 = getImage(getCodeBase(), image2Name);
    System.out.println("Preparing " + image1Name + " (" + image1 + ")");
    prepareImage(image1, this);
    System.out.println("Preparing " + image2Name + " (" + image2 + ")");
    prepareImage(image2, this);
  }

  public boolean imageUpdate(Image img, int infoflags, int x, int y, int width, int height)
  {
    if ( (infoflags & ImageObserver.ALLBITS) != 0 )
    {
      if ( img == image1 )
        System.out.println(image1Name + " is ready");
      else if ( img == image2 )
         System.out.println(image2Name + " is ready");
      else
         System.out.println(img + " is ready but it does not match any of the prepared images");
      }
     return true;
   }
} 
---------- END SOURCE ----------

Release Regression From : 6u10
The above release value was the last known release where this 
bug was not reproducible. Since then there has been a regression.