Notes/Domino 6 and 7 Forum : JDBC OracleDriver Error

I am trying to connect to an Oracle DB Server using JDBC and I am getting an error.
The Domino Server runs on AIX.
The code:
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
}
catch(java.lang.ClassNotFoundException e)
{
System.err.print("ClassNotFoundException: ");
System.err.println(e.getMessage());
}
catch(Exception e)
{
e.printStackTrace();
}

Error:
HTTP JVM: ClassNotFoundException:
HTTP JVM: oracle.jdbc.driver.OracleDriver

if I change the code to :
Class.forName("OracleDriver");

I get the following Error:
HTTP JVM: java.lang.NoClassDefFoundError: OracleDriver (wrong name: oracle/jdbc/driver/OracleDriver)
HTTP JVM: at java.lang.ClassLoader.findBootstrapClass(Native Method)
HTTP JVM: at java.lang.ClassLoader.findBootstrapClass0(ClassLoader.java:911)
HTTP JVM: at java.lang.ClassLoader.loadClass(ClassLoader.java:507)
HTTP JVM: at java.lang.ClassLoader.loadClass(ClassLoader.java:505)
HTTP JVM: at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:441)
HTTP JVM: at java.lang.ClassLoader.loadClass(ClassLoader.java:446)
HTTP JVM: at java.lang.ClassLoader.findSystemClass(ClassLoader.java:854)
HTTP JVM: at lotus.domino.AgentLoader.loadClass(Unknown Source)
HTTP JVM: at java.lang.ClassLoader.loadClass(ClassLoader.java:446)
HTTP JVM: at java.lang.Class.forName1(Native Method)
HTTP JVM: at java.lang.Class.forName(Class.java:142)
HTTP JVM: at JavaAgent.NotesMain(JavaAgent.java:31)
HTTP JVM: at lotus.domino.AgentBase.runNotes(Unknown Source)
HTTP JVM: at lotus.domino.NotesThread.run(NotesThread.java:208)

notes.ini contains the paths of Oracle Java Classes

when I run the same code outside Domino, it works.

I don't know why Domino can't find this class?