Magento {{depend}} directive for different contact forms

Question

I have created an additional custom email form for catalogue requests and added to a CMS page as follows:

{{block type="core/template" name="contactForm"     
 form_action="/contacts/index/post" template="contacts/myForm.phtml"}}

I have also created a different transactional email template, but I understand that I need to use the {{depend}} directive to be able to use one form or another. Can someone point me in the right direction. I added the following in the "Template Subject" field of the email template:

  {{if store url="catalogue-request"}}  Catalogue Request {{else}} New    
 Contact {{/if}} 

But unfortunately it behaves erratically. Sometimes I get the first subject line, some other times the second. Any idea what I am doing wrong?