Support Error

When I click on a support link inside the whmcs client area, I get this message at the top of the page:

Warning: HTTP Error:22/The requested URL returned error: 404 at http://www.mydomain.com/whmcs/viewticket.php?tid=639021&c=77MloRRc&systpl=portal in /home/mydomain/public_html/wp/wp-content/plugins/whmcs-bridge/includes/http.class.php on line 226

What can be wrong?

This us the support link:

http://www.mydomain.com/wp/whmcs-bridge/?ccce=viewticket&tid=639021&c=77MloRRc

Plus, the associated url I get in my email is:

http://www.mydomain.com/whmcs/viewticket.php?tid=639021&c=77MloRRc

..but that simply returns a 404.

I have absolutely no idea what could be wrong. Everything else seems to be working fine.

http://wordpress.org/plugins/whmcs-bridge/