can't install windows xp on a drive that has vista on it

I bought a hp pavillion that has vista home premium and I'm trying to
install XP on a separate partition. However, I cannot get the XP
installation cd to load: if I boot from it, windows loading crashes,
and if I insert the cd from within vista, the 'install windows' option
is disabled.
There's a microsof kb article at http://support.microsoft.com/kb/931760
describing my exact problem. And it says that certain bios will cause
xp to not load on a disk partitioned by vista, since it's a different
partition than xp expects. I changed the registry entries as it
suggested, but no result. Also, I emailed them about the hotfix and
they said vista home premium has no hotfix for this.
My question is, how am I supposed to install XP on this machine,
either as a dual boot or to completely remove vista, if I can't even
get the XP install cd to load?