Migrate VMWare to Virtualbox: Windows XP does not boot, hangs at agp440.sys

This can happen when attempting to boot a WinXP VM that was created in VMWare in a Virtualbox VM.

I needed to do 2 things to fix the problem.

Disable the agp440 service (apparently you can delete/rename the file also)
Set Enable IO APIC option.

Thanks to:
http://www.virtualbox.org/wiki/Migrate_Windows
http://support.microsoft.com/kb/324764
http://www.digizenstudio.com/blog/2008/05/20/vmware-to-virtualbox-migration-issues/