AffineTransform freezes my program

Question

I wrote a 2d program that simulates a bunch of rabbits, who run around the screen reproduce etc. When the rabbits move higher up on the screen they are scaled smaller to give a sort of perspective look. I have 3 images for left animation, 3 for up, 3 for down. When the rabbits are facing right, I scale them with a negative x value which flips the image around the vertical.
This all used to work perfectly fine until about a year ago when I got a later version of Java (can't remember which one, kind of gave up until now).
The problem seems to occur when the rabbits face left. They can run that way for a while (time varies), but then suddenly their images start repeating themselves in a row, horizontally, and then the program freezes.
So weird!
Here is a exert from the loop that renders each rabbit:
AffineTransform transform = new AffineTransform ();
Rabbit rab = (Rabbit) i.next ();
Image img;
if (rab.getState () == Rabbit.DEAD){
     img = Globals.gravestone;
     rab.direction = Rabbit.LEFT;
else
     img = rab.getImage ();
double scale = 0.25 * (rab.getAge () < 3 ? (rab.getAge () + 1) : 4) * (0.5 + (double) rab.y / getHeight () * 0.5);
int imgW = (int) (img.getWidth (null) * scale);
int imgH = (int) (img.getHeight (null) * scale);
if (rab.direction == Rabbit.RIGHT){
     transform.translate (rab.x + imgW / 2, rab.y - imgH / 2);
     transform.scale (-scale, scale);
else{
     transform.translate (rab.x - imgW / 2, rab.y - imgH / 2);
     transform.scale (scale, scale);
g.drawImage (img, transform, null);This is in a method render() within a JFrame, so getHeight() or getWidth() refer to that of the JFrame. The rabbits are also scaled depending on their age.
Any help or explanations would be great. Thanks

Answer 1

Here is the stack state when the command "new JFileChooser()" freezes my program:
copyFirstPIDLEntry() : -1, sun.awt.shell.Win32ShellFolder2, Win32ShellFolder2.java
createShellFolderFromRelativePIDL() : 57, sun.awt.shell.Win32ShellFolderManager2, Win32ShellFolderManager2.java
getLinkLocation() : 622, sun.awt.shell.Win32ShellFolder2, Win32ShellFolder2.java
isDirectory() : 471, sun.awt.shell.Win32ShellFolder2, Win32ShellFolder2.java
get() : 200, sun.awt.shell.Win32ShellFolderManager2, Win32ShellFolderManager2.java
get() : 221, sun.awt.shell.ShellFolder, ShellFolder.java
updateUseShellFolder() : 500, com.sun.java.swing.plaf.windows.WindowsFileChooserUI, WindowsFileChooserUI.java
installComponents() : 203, com.sun.java.swing.plaf.windows.WindowsFileChooserUI, WindowsFileChooserUI.java
installUI() : 136, javax.swing.plaf.basic.BasicFileChooserUI, BasicFileChooserUI.java
installUI() : 140, com.sun.java.swing.plaf.windows.WindowsFileChooserUI, WindowsFileChooserUI.java
setUI() : 650, javax.swing.JComponent, JComponent.java
updateUI() : 1755, javax.swing.JFileChooser, JFileChooser.java
setup() : 366, javax.swing.JFileChooser, JFileChooser.java
<init>() : 332, javax.swing.JFileChooser, JFileChooser.java
<init>() : 285, javax.swing.JFileChooser, JFileChooser.java