Custom post type receives no trackbacks?

Hello,

I set up a new custom post type a while back and recently discovered that it was not receiving trackbacks/pingbacks.

When I looked at it, I discovered that “trackbacks” was not listed under “supports” where register_post_type() is called in functions.php.

I added it right away, but I am still not receiving any trackbacks/pingbacks.

Question: Is it not possible to add/remove modules in “supports” in register_post_type() after WP has begun using a post type?

Question 2: If it is supposed to be possible, does anybody have any other ideas on how I can troubleshoot my missing trackbacks?

Thanks.