Hooks Not Working In Invoice.tpl

I am trying to make modifications to the invoice.tpl file and trying to use the built in hooks. I have the hook files in the orders folder under the My Changes/hooks/ (just like my other hook modifications) but no amount of flushing cache or reloading screens gets them to work. If I modify the invoice.tpl file itself I see my changes but nothing shows up if I use hooks. Anybody have any thoughts or comments?



mail is a separate area than 'customers' and 'admin'. Hence it needs hooks installed in its own directory structure. Eg.


Thanks EZ - that did the trick!