OPERATING SYSTEM(S):
Redhat Enterprise Linux AS version 4(RHEL4), and RHEL4+Update1.
RHEL3, SLES9.

FULL JDK VERSION(S):
java version "1.5.0_03"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_03-b07)
Java HotSpot(TM) Client VM (build 1.5.0_03-b07, mixed mode)

DESCRIPTION:
Steps to Recreate:
1. Download these input method tools.
http://java.sun.com/products/jfc/tsc/articles/InputMethod/InputMethodHotKey.jar
http://java.sun.com/j2se/1.5.0/docs/guide/imf/spi-sample/CityIM.jar

2. Launch InputMethodHotKey.jar and define a hot key combination. such as Shift+F4
$ java -jar InputMethodHotKey.jar

3. Install CityIM.jar into jdk/jre/lib/ext directory.

4. Launch JTextArea with XAWT. For example, notepad demo (demo/jfc/Notepad/Notepad.jar).
$ java -jar Notepad.jar

5. Press the key combination you chose in step 2, and choose City Input Method.
    Any language of CityIM can recreate the problem.

6. Type "tyo" and press space key twice to invoke lookup window.

7. Click the application window.

Result
Lookup window was covered by the JTextArea window.

Expected Result
Lookup window should be always displayed on the front.

Additional Information:
This problem doesn't occur with Motif Toolkit.