FULL PRODUCT VERSION :
java version "1.7.0-ea"
Java(TM) SE Runtime Environment (build 1.7.0-ea-b71)
Java HotSpot(TM) Client VM (build 16.0-b08, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [version 6.0.6002]

A DESCRIPTION OF THE PROBLEM :
Typing a @ in a JTextArea when running over JRE7 delete the following character. Typing a ' first move the cursor to the next character then insert '

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
run the following code with JRE7b71 then insert a few blank lines (say 3 times) then type 'test', then type @  on the first line, set the cursor between the e and s of test then type '

import java.awt.Dimension;
import javax.swing.JOptionPane;
import javax.swing.JTextArea;
public class Main {
    public static void main(String[] args) {
      JTextArea jta = new JTextArea();
      jta.setPreferredSize(new Dimension(200, 200));
      JOptionPane.showMessageDialog(null, jta);
    }
}


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The content of the JTextArea should be:
@


te'st
ACTUAL -
The content of the JTextArea is:
@

tes't

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.awt.Dimension;
import javax.swing.JOptionPane;
import javax.swing.JTextArea;
public class Main {
    public static void main(String[] args) {
      JTextArea jta = new JTextArea();
      jta.setPreferredSize(new Dimension(200, 200));
      JOptionPane.showMessageDialog(null, jta);
    }
}

---------- END SOURCE ----------

Release Regression From : 6u13
The above release value was the last known release where this 
bug was not reproducible. Since then there has been a regression.