Running jarsigner -verify with Mantis b06 and later on a jar file signed with
Netscape signtool 1.3 causes a ZipException:

$ /space/j2sdk1.4.2/bin/jarsigner -verify RMiimjni.jar
jarsigner: java.lang.IllegalStateException: zip file closed

The same command with jarsigner from JDK 1.3.1 or 1.4.1 verifies the JAR.

A sample JAR file signed with Netscape signtool 1.3 is attached.