Kernel packages/header question

[snacktime <snacktime@gmail.com>]

I'm running debian testing with kernel 2.4.27-2-686-smp.  I'm trying
to compile the zaptel kernel modules which needs the kernel source. 
I've done it before on other boxes that aren't smp boxes without any
problems, but I'm missing something here in getting the right source,
headers, or something.

I downloaded   kernel-source-2.4.27, linked it to /usr/src/linux, ran
makemenuconfig, saved and exited then ran make dep.

I'm a bit confused about whether I need the kernel headers, and which
ones I need.  I haven't needed them on boxes without smp, but there
are no smp specific header packages for this kernel anyways.

zaptel compiles but with these results:

if [ -d /etc/modutils ]; then \
        /sbin/update-modules ; \
fi
depmod: *** Unresolved symbols in /lib/modules/2.4.27-2-686-smp/misc/wcusb.o
depmod: *** Unresolved symbols in /lib/modules/2.4.27-2-686-smp/misc/zaptel.o
depmod: *** Unresolved symbols in /lib/modules/2.4.27-2-686-smp/misc/ztd-eth.o
[ `id -u` = 0 ] && /sbin/depmod -a || :
depmod: *** Unresolved symbols in /lib/modules/2.4.27-2-686-smp/misc/wcusb.o
depmod: *** Unresolved symbols in /lib/modules/2.4.27-2-686-smp/misc/zaptel.o
depmod: *** Unresolved symbols in /lib/modules/2.4.27-2-686-smp/misc/ztd-eth.o
[ -f /etc/zaptel.conf ] || install -D -m 644 zaptel.conf.sample /etc/zaptel.conf


modprobe zaptel
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o:
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o: unresolved symbol
create_proc_entry_Rsmp_c9aa57a7
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o:
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o: unresolved symbol
remove_wait_queue_Rsmp_b71057fd
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o:
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o: unresolved symbol
__pollwait_Rsmp_deb8b597
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o:
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o: unresolved symbol
register_chrdev_Rsmp_01679e76
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o:
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o: unresolved symbol
remove_proc_entry_Rsmp_cd9b223d
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o:
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o: unresolved symbol
add_wait_queue_Rsmp_0bd2c631
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o:
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o: unresolved symbol
proc_mkdir_Rsmp_7e5ce3f4
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o: insmod
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o failed
/lib/modules/2.4.27-2-686-smp/misc/zaptel.o: insmod zaptel failed