JDBC thin driver loading problem

 I would appreciate any help you might be able to provide. I am trying to test a JBuilder program. It works under JBuilder, but when I deploy, including the oracle thin drivers in the jar file, I get a

             no suitable driver
error.
the string is:
 jdbc:oracle:thin:@MACHINE:1521:DB1

I have tried registering the driver in two ways. I have packaged the oracle thin driver package classes111.zip, and oracle 8.1.5 is running on linux RH6.0
I get a SQLException:
  SQLState: 08001
  Message: No suitable driver
  Vendor: 0
When I test with JBuilder3, it works, but fails at this point when I test with Opera5.02 running the JVM1.3. (Also, when I test with NS with the java plugin, I get a notinited problem).

thanks in advance for any help,
Rachel

I have tried with both these options for driver registration and connection:

    String url = jdbc:oracle:thin:@MY_MACHINE:1521:DB1;     try
{

      /*
       * Load the Oracle JDBC driver
       */
      Class.forName("oracle.jdbc.driver.OracleDriver");

      conn = DriverManager.getConnection (url, user_id, password );

.....
}

and I have also tried:

    String url = jdbc:oracle:thin:@MY_MACHINE:1521:DB1;     oracle.jdbc.driver.OracleDriver oracleDriver = null;     try
{

      /*
       * Load the Oracle JDBC driver
       */
      oracleDriver = new oracle.jdbc.driver.OracleDriver ();
      DriverManager.registerDriver(oracleDriver);
      conn = DriverManager.getConnection (url, user_id, password );