Finally managed to resolve this (with help from the Ubuntu Launchpad folks) by setting noapic/nolapic/nomodeset in /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="noapic nolapic nomodeset splash quiet"
Had to carry out the following:
sudo nano /etc/default/grub
Ctrl+O to save
Ctrl+X to exit
I think that the one that actually made the difference was the nomodeset. Hope that helps someone out there experiencing the same issues.