problems applying ipset patch

hi, this is my first post here. [don't know if I have to use the developer mailing list, sorry if i'm wrong].

I've tried to apply the ipset patch in my CentOS 4.4 distribution, without success.

I've followed instructions here http://www.howtoforge.com/kernel_compilation_centos_p2?s=aabdb730a09fa747d00f2b9a3ff431cc&
(CentOS Kernel Compile) and here
http://ipset.netfilter.org/install.html (ipset patch apply).

The patch is applied successfully, but when I try to recompile, I obtain these errors (after a long list of compiled files):

...
LD .tmp_vmlinux1
net/built-in.o(.init.text+0x16f1): In function `ipt_ipset_init':
net/ipv4/netfilter/ipt_set.c:133: undefined reference to xt_register_match' net/built-in.o(.init.text+0x1700): In function ipt_SET_init':
net/ipv4/netfilter/ipt_SET.c:151: undefined reference to xt_register_target' net/built-in.o(.exit.text+0x41): In function ipt_ipset_fini':
net/ipv4/netfilter/ipt_set.c:138: undefined reference to xt_unregister_match' net/built-in.o(.exit.text+0x50): In function ipt_SET_fini':
net/ipv4/netfilter/ipt_SET.c:156: undefined reference to `xt_unregister_target'
make: *** [.tmp_vmlinux1] Error 1

I've tried twice, using two combinations of kernel (downloaded from www.kernel.org) and patch-o-matic (downloaded first time from http://ipset.netfilter.org/, second from patch-o-matic snaptshots).

I've applied only the ipset patch (launching only the ./runme set command, just as explained in the ipset site).

Maybe do I need to apply other patches from patch-o-matic?

Thanks for the help