I notice that there are some recent security updates for the 2.4.27 kernel. Will aptitude update/ aptitude upgrade install these security patches or do I have to dist upgrade or what?

aptitude update, as far as I know, only updates your sources (like "tells" apt what new packages there are available), so in addition to doing "update" you need to either "install" the packages by name (if they're new) or do "upgrade". A "dist-upgrade", I think, upgrades each and every possible application you have installed if there is a newer version.

So, if you just want the security updates, I'd upgrade them by name. I hardly ever do that for single packets only, but doing "upgrade" to the specified packages should do, if I'm right.

OK, I understand that is the case for packages. But I'm wondering if it also upgrades the kernel if you see what I mean.

The kernel itself is still treated like a package, if the kernel-image-2.4.27 package has been updated then dist-upgrading will replace it with a new version, security patches and all. When or if these patches make it to sarge is up to the Debian kernel team.

Thanks guys