I have been getting this error when running make modules_install since
kernel 2.5.38:
Installing modules in /lib/modules/2.5.40/kernel/lib
make[1]: Leaving directory `/rad000/users/tspace/smarz/linux-2.5.40/lib'
make[1]: Entering directory
`/rad000/users/tspace/smarz/linux-2.5.40/arch/i386/lib'
make[1]: Leaving directory
`/rad000/users/tspace/smarz/linux-2.5.40/arch/i386/lib'
if [ -r System.map ]; then /sbin/depmod -ae -F System.map 2.5.40; fi
depmod: *** Unresolved symbols in
/lib/modules/2.5.40/kernel/net/ipv4/netfilter/ipt_owner.o
depmod: next_thread
depmod: find_task_by_pid
make: *** [_modinst_post] Error 1