Install JDK1.3.1_18 on Win XPPro X86
Copy the TZupdater b04 tool from /java/re/tzupdater131/1.0.1/promoted/fcs/b04/bundles
Unzip the bundle and run:

$ java -jar tzupdater131.jar -u
Backing up C:\Program Files\JavaSoft\JRE\1.3.1_18\lib\rt.jar to C:\Program Files
\JavaSoft\JRE\1.3.1_18\lib\rt.jar.TZbackup
java.util.zip.ZipException: invalid entry crc-32 (expected 0x0 but got 0x3619558a)
        at java.util.zip.ZipOutputStream.closeEntry(Unknown Source)
        at java.util.zip.ZipOutputStream.putNextEntry(Unknown Source)
        at java.util.jar.JarOutputStream.putNextEntry(Unknown Source)
        at sun.tools.jar.Main.update(Unknown Source)
        at sun.tools.jar.Main.run(Unknown Source)
        at com.sun.tools.tzupdater131.TimezoneUpdater131.updateRtjar(TimezoneUpdater131.java:378)
        at com.sun.tools.tzupdater131.TimezoneUpdater131.run(TimezoneUpdater131.java:203)
        at com.sun.tools.tzupdater131.TimezoneUpdater131.main(TimezoneUpdater131.java:633)
Failed to update temporary rt.jar
$
$ java -version
java version "1.3.1_18"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1_18-b01)
Java HotSpot(TM) Client VM (build 1.3.1_18-b01, mixed mode)
$

We've crossed-checked the system with Win2K and also 1.3.1_19
NOTE: Private JRE worked fine.

TASTERS # /jdk1.3.1_18/jre/bin/java -version
java version "1.3.1_18"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1_18-b01)
Java HotSpot(TM) Client VM (build 1.3.1_18-b01, mixed mode)
TASTERS #
TASTERS # /jdk1.3.1_18/jre/bin/java -jar tzupdater131.jar -u
This JRE was previously updated.