Function set_value() not working as expected

[eluser]beachbum[/eluser]
I have the following html/php & codeigniter in my view for my contact form:

Code:

<input type='text' name='phone' id='phone' value="<?php echo set_value('phone'); ?>" />

I have used the set_value() function in all of the other fields in this form, and it works like a charm. However, it never works for this field, and I can't understand why it doesn't.

Incidentally, the "phone" field is the only field in the form (besides the submit button) for which I have not used any validation with the form_validation library. That is the only anamoly that I've been able to find, but the fact that I didn't set a validation rule for this field should not prevent the set_value() function from working, should it?

Thanks!

Contact form