FULL PRODUCT VERSION :
java version "1.5.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)
Java HotSpot(TM) Client VM (build 1.5.0-b64, mixed mode)

A DESCRIPTION OF THE PROBLEM :
There's a comment in the javadoc for java.util.jar.Attributes.writeMain():

 "XXX Need to handle UTF8 values and break up lines longer than 72 bytes"

The API docs for the Attributes class state:

"Attribute values can contain any characters and will be UTF8-encoded when written to the output stream."

This has been the case since 1.2.2 at least.

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
Don't use java.util.jar.Manifest if there's any chance of an attribute value being in some multi-byte encoding.