Lazy Approval - the unique reference is not showing on the e-mail.

I have a form, but when submitted the user gets an e-mail back, but the unique reference does not show on the subject line of the e-mail. I originally thought it was a currupt workflow so re-wrote the form and the workflow  - still the same issue, I wrote a test lazy approval form, and this worked fine. I have no issues with any other workflows, lazy approval is working fine. I'm stumped!