Java Database Connectivity (JDBC)

I'm running tomcat 5.5 with SQL Server 2000. I'm working on adding transaction support through UserTransaction with JOTM.

I installed JOTM, a Transcation Manager, but it doesn't seem to work. When I try to rollback an update, it still commits it.

###My code (snippet):

Connection con = DAOUtil.getConnection();
        String sqlStmt = "INSERT INTO Building (Street, City, State, Zip, CLLI, " +
                       "SWC, ContactName, ContactPhone, CommonName) " +
                       "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
      PreparedStatement saveBuilding = null;

            Context ctx = new InitialContext();

            UserTransaction ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");

            ut.begin();

            saveBuilding = con.prepareStatement(sqlStmt, Statement. 
                                       RETURN_GENERATED_KEYS);
         
            saveBuilding.setString(1, building.getStreet());
            ...

           saveBuilding.execute();

            ut.rollback();       //THIS DOESN'T WORK

###Server.xml:

   
<Server>
<GlobalNamingResources>
   <Resource auth="Container" name="UserTransaction" 
                       type="javax.transaction.UserTransaction" 
                       jotm.timeout="60" 
                       factory="org.objectweb.jotm.UserTransactionFactory" />

      <Resource name="jdbc/cafe" 
                           type="javax.sql.DataSource" 
                           driverClassName="net.sourceforge.jtds.jdbc.Driver" 
                           password="XXX" 
                           maxIdle="5" 
                           maxWait="300" 
                           validationQuery="Select Val From ValueItem" 
                           username="ABC" 
                           url="jdbc:jtds:sqlserver://SERVER_NAME:1433;
                           DatabaseName=ABCD;" 
                           factory="org.objectweb.jndi.DataSourceFactory" 
                           maxActive="10" />
</GlobalNamingResources>
</Server>

###domain.xml:

<Context displayName="CaFE" 
                      docBase="CaFE" 
                      path="/CaFE" 
                      reloadable="true" 
                      workDir="C:\Tomcat-5.5\webapps\CaFE\work">

    <ResourceLink global="UserTransaction" 
                               name="UserTransaction" 
                              type="javax.transaction.UserTransaction"/>

   <ResourceLink global="jdbc/cafe" 
                              name="jdbc/cafe" 
                              type="javax.sql.DataSource"/>
</Context>

I'm able to read/get the UserTransaction from the JNDI tree. But for some reason the transaction doesn't work.

Any ideas?

Thanks in advance.