Trackback Links don't display in custom content types from CCK

If I enable trackbacks for default content types, I have no problems. The trackback displays at the bottom of the content. But when I try to use them on custom content types (which, it turns out, is the only place i need them on this site) the trackback link is not displayed at all.

I'm guessing this is because the CCK module doesn't use $content to show the content of the page, and the trackback module adds the 'box' with the link into $content. I'm about to try the z_index module method, but I really feel like I'm grasping at straws here... it looks like it was developed for 4.6, and not only am I not aware of any subtle differences between the two versions, but I'm pretty sure even though the rest of the steps are clearly outlined, the module itself isn't included, and I might not be able to find it on the Drupal site, or anywhere else, for that matter.

Has anyone else run into this problem, is there an easier way to fix it? (maybe work with CCK to use $content? or update trackback to use something more universal?)

any help much appreciated!
Jen