/lib/modules/$(uname -r)/build is pointing into the build system root
(/usr/src/bs/BUILD/kernel-2.4.0/linux) as opposed to /usr/src/linux-2.4.0
which breaks building external modules. This is the case in at least both
of 2.4.0-0.99.5 and 2.4.0-0.99.9
This defect is considered MUST-FIX for Florence Release-Candidate #1
I think I have a handle on this, potential fix is in CVS
the symlink is to ../../../usr/src/linux-2.4.0
but it works.