JRE 6u1 fails plugin test on some windows Vista machines

From what the L10N team reported, jre-6u1-*-windows-i586.exe bundle on Vista (ja) passed, but jdk-6u1-*-windows-i586-iftw.exe bundle on Vista (zh) failed plugin test.

The sympton reported is as follows:

1. Download and install 6u1 (jdk-iftw.exe) on Windows Vista/2003 (zh)

2. click on the "this <http://webeng.sfbay/plugin-test/>" link to go to the test page.

3. click on "Test Install" link for the corresponding release version ( 6u1) to begin testing.

Problem:

It prompts to install 6u1 again.

A machine with which the failure can be reproduced is in Beijing with Vista zh_CN locale.
The problem can be reproduced on any windows Vista machine which doesn't have the msvcr71.dll in the C:\windows\system32 directory.