where did kernel-2.6.18-1.2869.fc6 go?

[Jack Howarth]

   I am about to upgrade a FC4 box to FC6 and am greatly
concerned about the unstable state of both 2.6.19 kernel
releases so far. A second machine running the latest
kernel-2.6.19-1.2911.fc6 kernel exhibits strange memory
problems and on a third machine the same kernel exhibited
major slowdowns after mounting and unmounting external
usb drives. I was going to use the same kernel-2.6.18-1.2869.fc6
release that seems stable on those FC6 machines when I did
the new upgrade. However I don't see the kernel-2.6.18-1.2869.fc6
release in the updates directory now for FC6. What is that about?
Why would Fedora remove the last stable kernel and leave us with
either the original FC6 kernel or 2.6.19? Thanks in advance for
any clarifications.
         Jack