FULL PRODUCT VERSION :
java version "1.4.2_03"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_03-b02)
Java HotSpot(TM) Client VM (build 1.4.2_03-b02, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
Delete characters using the Backspace key deletes the characters not only in the Input Window but also in the client component

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Install the City Input Method (http://java.sun.com/j2se/1.4.2/docs/guide/imf/spi-sample/CityIM.jar) by copying the .jar file into the jre\lib\ext directory
2. Launch jEdit (www.jedit.org)
3. Type some text
4. Activate input method, selecting English for City IM
5. Start composing by typing some text in the Input Window. Do not commit the text yet
6. Hit Backspace key to delete characters of composed text in the Input Window

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Backspace should delete characters of the composed text in the Input Window only
ACTUAL -
Not only text in the Input Window got deleted, so was text in the client component.

This bug exists in Tiger Beta also.

REPRODUCIBILITY :
This bug can be reproduced always.