Yeah, we liked the idea of trackback and wanted to use it, even though we've never used MovableType stuff. So we went and read up on how it worked, paying extra attention to this part:

Changes

1.1 (October 10, 2002)

* TrackBack pings should now be sent using HTTP POST instead of GET. The old behavior is deprecated, and support for GET will be removed in January 2003.

cip, who's so clever, started hammering on the code and by January 20, 2003, we had trackback weee!

It's been more than a year now, and still so many, oh so many, people out there are using the old trackback rather than the new... And when they get frustrated by failed tries, they email or comment dissapointed "...your trackback isn't working..?". Ah, but see.... It actually is! Honest!

Remember:
* TrackBack pings should now be sent using HTTP POST instead of GET. The old behavior is deprecated, and support for GET will be removed in January 2003.

Anyway, this post was just to let you know, in case you were/are a trackback-person having trouble. We're just so bleeding edge! ;P