That's a good guide but I'd install the Ubuntu kernel source package and compile that one instead of a vanilla one from kernel.org. That way everything you have now will work after changing that couple parameters.
If you're using restricted modules, make sure you create a symlink to the exact name of your new kernel inside /lib/modules
to ensure that the firmwares are loaded. The symlink should point to an existing kernel module directory.
For example, if your existing kernel is 2.6.17-10-generic
, there should be a folder called exactly like that inside /lib/modules
. You'll want your new kernel to use those modules (since it's the same kernel source with a couple configuration tweaks). If your new kernel ends up being named something like 2.6.17-10-generic-custom
, then make a link inside /lib/modules
that points to /lib/modules/2.6.17-10-generic