Build single jar with libraries

I am trying to build a single jar file for my project with all other libraries included (database drivers, etc). The build process works fine and I am able to create the jar. I am using Netbeans IDE for the same.

My problem: When I run the jar file directly by double clicking it, jdbc (sqlite) driver doesn't work. Although when I run it from command line using java -jar myproject.jar, it works fine.

Here's the portion of build.xml that I use for making a single jar:

<target name="-post-jar">
<property name="store.jar.name" value="myproject"/>
<property name="store.dir" value="dist"/>
<property name="store.jar" value="${store.dir}/${store.jar.name}.jar"/>
<echo message="Packaging ${application.title} into a single JAR at ${store.jar}"/>
<jar destfile="${store.dir}/temp_final.jar" filesetmanifest="skip">
    <zipgroupfileset dir="dist" includes="*.jar"/>
    <zipgroupfileset dir="dist/lib" includes="*.jar"/>
    <manifest>
        <attribute name="Main-Class" value="${main.class}"/>
    </manifest>
</jar>
<zip destfile="${store.jar}">
    <zipfileset src="${store.dir}/temp_final.jar"
    excludes="META-INF/*.SF, META-INF/*.DSA, META-INF/*.RSA"/>
</zip>
<delete file="${store.dir}/temp_final.jar"/>
</target>

Also interestingly, all other libraries (like jcalender) that I've used work well, except sqlite-jdbc. Any thoughts on why this may be happening?

Note : I also don't get any exceptions, ClassNotFoundException or such.