Why is my custom template tag not being parsed?

[snugRugBug]

I'm creating an application which displays a template when my custom template tag is used. It works fine on my dev install, and I successfully tested it on a fresh local install, but on our big test site the template tag is not being recognized at all.

To clarify, my template tag looks like this:

{myawesomewidget='123'}

When I insert the tag into a template it should output a template containing my awesome widget:

-------------MY AWESOME WIDGET------------

But on our big test site it outputs the unaltered template tag:

{myawesomewidget='123'}

So somehow it just fails to parse it. Any ideas on how to troubleshoot this?