There was thread recently with the same problem. I suggested to delete the old modules tree /lib/modules/2.4.18 and then let modules_install recreate tree with just the modules required. It sounds like a broken makefile. But anyway, the thread is here:
http://www.linuxquestions.org/questi...threadid=45124
I think the final resolution was to build from a fresh kernel source to avoid the depmod errors.
Perhaps it might help in some way.