How to reset a broken content template?

Hi! I was trying to modify the output of a CCK created content, using the contemplate module. I was trying to u use a new php function that I included in my template.tpl.php file, but now it tells me that I am using a not declared function and it give me error if I try to edit the template for that content. If I remove the content type and then I create it with the same name, the content template is still there and not editable. So removing the content type does not reset the template.
How can I reset then that content template???

Thank you!
G.P.