form_open() url problem

[eluser]sohei[/eluser]
Hi everybody!
I have a problem with my form, I open it with "form_open('email/send')" and he redirect me on "www.example.com/ci/index.php/index.php/email/send. Yes, with two "index.php" directory . Anyone know why?

Code:

<?php echo form_open('email/send') ;?>
//inputs
<?php echo form_submit('submit','Submit'); ?>
<?php echo form_close() ;?>

Thanks,
sohei