set_value is only working for fields that have validation?

[eluser]otherjohn[/eluser]
Hi all, I am using form validation on a page and for some reason only input fields that I have set form valitation rules to will auto fill. The rest are blank. Does anyone know how to fix this?
For example
if I have something like "firstname" required

Code:

$this->form_validation->set_rules('firstname', 'First Name', 'required');

and on the view have

Code:

<input id="firstname" name="firstname" type="text" class="field text" value="<?php echo set_value('firstname'); ?>" size="8" tabindex="10" />

AND

Code:

<input id="lastname" name="lastname" type="text" class="field text" value="<?php echo set_value('lastname'); ?>" size="14" tabindex="11" />

LASTNAME input doesn't auto fill but firstname does.
Validation works correctly though. Any thoughts?