vulnerability ?

[norm <norm@xxxxxxxxxxxxxxx>]

I recently ran a security scan on my system and the result in part was
The remote host is missing the patch for the advisory FEDORA-2006-172
(xorg-x11-server).  It advises me to update my system using the latest
from Fedora. To the best of my knowledge I am running a fully patched
system with 2.6.17-1.2187_FC5.  
This is a vulnerability that I understand to have been around for a
while and I assume in the intervening 6 months or so it has been
patched.  Does anyone know if this vulnerability is a false positive?
Norm