SQLite JDBC driver not working in Win 7 and Ubuntu

Question

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 in windows 7 or Ubuntu, jdbc (sqlite) driver doesn't work. Although when I run it from command line using java -jar myproject.jar, it works fine. Also it is working fine in Windows 8 and Mac OS by double clicking.

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.

Edits :

1. When I use a print statement (by which I mean writing to a file) before and after the jdbc connection statement, nothing happens in win 7/ubuntu.

2. I tried using the same version of jre as that of Mac OS and Win 8 (i.e. jre 1.8) on ubuntu, thinking that maybe that was causing some problems. But nope, no luck there.

My database connection code :

        Class.forName("org.sqlite.JDBC");            
        SQLiteConfig config = new SQLiteConfig();  
        config.enforceForeignKeys(true);  
        System.out.println(config.toProperties());
        ErrorLog.write_to_file("fetching connection");            
        Connection conn = DriverManager.getConnection("jdbc:sqlite:Data.db",config.toProperties());
        Statement stmt=conn.createStatement();
        ErrorLog.write_to_file("connected");

The ErrorLog class writes errors to a file. Also please note that this portion is in a try-catch block. In the catch block, I again use ErrorLog to write to file

I've put the database file in the same folder as the jar file.