WP not sending/recieving Trackbacks

After looking through google, this forum and trying some fixes I’ve finally decided to post at this support forum about my question.
My journal is located at http://chenu-j.net and I’ve been having problems sending and recieving trackbacks on my journal since I started blogging.
Trackbacks weren’t a feature I used much so I really didn’t worry about it until now, I have articles I want to trackback to but I can’t.
I’ve tried a fix by http://iozblog.ionosfera.com/archives/2004/08/29/wordpress_trackback_fix/ but it didn’t fix anything.
The way I’ve been testing trackbacks is through another blog installed at http://chenu-j.net/lab and I’ve tried trackbacks to other popular weblogs such as http://spreadfirefox.com and they don’t appear.