Loadable kernel modules not unloadable

["hillbilly" <bennitech@bluep.com.au>]

Can ANYONE help?
I am trying to prevent parport (and parport_pc, lp) from loading at
bootup on Deb Sarge with no success short of brute force (hiding the
actual module from the OS) which results in ugly messages about
undefined symbols and is at best potentially dangerous (for other
modules with more interdependence, anyway).  I have tried blacklisting
in hotplug, skip(ping) in discover, "alias parport off" in
modprobe.d/(various files???), rebuilding initrd.img without the
parpoort modules present, all methods at the same time, etc. and
NOTHING WORKS PROPERLY!  Either the modules load or lots of ugly
messages on boot up.  Rhetorical question:  what is the point in a
loadable module if you still need to rebuild the kernel (or all the
modules, at least) with the unwanted module excluded to prevent the
module from loading?

Is there a correct, consistent, centralised way of stopping a module
from loading?