Should work...
Only thing I'd say, is, whenever I do format parameters, I don't use spaces...
So the format parameters on one option on my Registration Form Timer add-on look like:
Code:
error={xen:phrase reg_form_error}
redirect={xen:phrase reg_form_redirect}
success={xen:phrase reg_form_success}
Maybe the space between the option ID and the text is breaking it somehow?