For older hardware you might have better luck with the alternative CD,
depending on how old it is.

You could also try turning of acpi. When the installer menu comes up,
press Esc. You will get a message about leaving the graphical menu.
Click OK. You'll get a boot: prompt.
Enter live acpi=off so your boot prompt looks like
boot: live acpi=off



The Ubuntu installer help also has some other suggestions (Press F1
when the installer boot menu appears):
- If you experience lockups or other hardware failures, disable buggy
APIC interrupt routing: noapic nolapic
boot: live noapic nolapic

- Disable ACPI for  PCI maps (handy for some HP servers and Via-based
machines): pci-noacpi
boot: live pci-noacpi

-- 
Andrew S. Zbikowski | http://andy.zibnet.us
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