FULL PRODUCT VERSION :
java version "1.6.0-beta2"
Java(TM) SE Runtime Environment (build 1.6.0-beta2-b83)
Java HotSpot(TM) Client VM (build 1.6.0-beta2-b83, mixed mode, sharing)

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

A DESCRIPTION OF THE PROBLEM :
Updating jar file with manifest file does not pick up changes to manifest in the jar file. The contents are picked up if the jar file is created with the manifest file. This did work in 1.4.2.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a text file with manifest entries ( manifest.txt )
Create a jar file ( jar cf foo.jar somefiles )
Update jar file with manifest ( jar ufm foo.jar manifest.txt )
Extract jar ( jar xf foo.jar )
Examine contents of manifest file ( type META-INF\MANIFEST.MF )

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expected entries of manifest.txt to be included.
ACTUAL -
Contained only default manifest entries:
Manifest-Version: 1.0
Created-By: 1.6.0-beta2 (Sun Microsystems Inc.)

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
Create jar file with manifest file instead of updating it.

Release Regression From : 5.0u7
The above release value was the last known release where this
bug was not reproducible. Since then there has been a regression.