jar tool with -C option does not work in a certain usage.

FULL PRODUCT VERSION :
java version "1.6.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-beta-b59g)
Java HotSpot(TM) Client VM (build 1.6.0-beta-b59g, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]
Microsoft Windows 2000 Professional

A DESCRIPTION OF THE PROBLEM :
for example:
the current directory have a sub directory tree like this:
classes\a\B.class
I execute jar command like this:
jar cvf my.jar -C classes/ .
and my.jar is not correct, the problem is my.jar file includes "classes" folder and no any thing in the folder.
This usage was shown in the jar tool's command-line help example2.

when I change the "/" to "\" or just delete "/" in the command, no problem occur.
the command is
"jar cvf my.jar -C classes\ ." or "jar cvf my.jar -C classes ."


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
always


REPRODUCIBILITY :
This bug can be reproduced always.