SuSE 6.4 security patches.

Hi all, I run SuSE 6.4 on one of my 2 servers... This machine is a firewall and an ISDN gateway .. I believe the stock 2.2.14-5.0 kernel has some security problems ... Would an upgrade of lx_suse solve the problem ? On my laptop I've installed 2.2.18 from a tarball... but on the server i would like to keep the SuSE patches to the kernel, intact....... How should I go about the upgrade ... what are the gotchas that i should look out for ? How should I prepare for the upgrade ? Thanks in advance Anurag