Oracle Forms

Hi All,
I amd using forms10g,oracle10g
I am facing a error while running a procedure to send mail from db
procedure is:

declare
ErrorMessage VARCHAR2(4000);
ErrorStatus NUMBER;
-- enable SQL*PLUS output;
--SET SERVEROUTPUT ON
-- redirect java output into SQL*PLUS buffer;
--exec dbms_java.set_output(5000);
BEGIN
ErrorStatus := SendMailJPkg.SendMail(
SMTPServerName => '192.168.4.2',
Sender => 'jagan@hafele.co.th',
Recipient => 'jebesh_s@yahoo.co.in',
CcRecipient => '',
BccRecipient => '',
Subject => 'hth106: Test JavaMail',
Body => 'This is the body: Hello, this is a test that spans 2 lines',
AuthReqdYNNum => 1,
UserID => 'jagan',
Password => 'songbirds',
ErrorMessage => ErrorMessage,
Attachments => SendMailJPkg.ATTACHMENTS_LIST('C:\oramail\MHTHSO_GEN45.html')
);
END;
/
while running this procedure i am receiving following error

"ORA-29532: Java call terminated by uncaught Java exception:
java.lang.IncompatibleClassChangeError"
but the same procedure sending mail from all other user in the same database

I am very myuch confused.i have given the all rights
below mentioned rights are given .it is working in all other user on the same db except this user "hth106". And all the othere things are compared between working user and this hth106 user every things are same.But i am receiving error when i sending mail with attachment if the mail is sending without attachement it is working fine

below rights are given to this user
---------------------------------------
1.exec dbms_java.grant_permission('HTH106','java.util.PropertyPermission','*','read');

2.exec dbms_java.grant_permission('HTH106','java.util.PropertyPermission','*','write');

3.exec dbms_java.grant_permission('HTH106','java.net.SocketPermission','*','connect');

4.exec dbms_java.grant_permission('HTH106','java.net.SocketPermission','*','resolve');

5.exec dbms_java.grant_permission('HTH106','java.io.FilePermission','C:\oramail\*','read');
exec dbms_java.grant_permission('HTH106','java.io.FilePermission','C:\oramail\*','write');

6.call dbms_java.grant_permission('HTH106','java.net.SocketPermission','HTHDS01','resolve');
7.call dbms_java.grant_permission('HTH106','java.util.PropertyPermission','*','read,write');
7.call dbms_java.grant_permission('HTH106', 'java.io.FilePermission','C:\oramail\*','read');


please advise me to proceed further

Thanks in advance

Thanks ,
Antony