Howdy El Sid! It looks like from you lspci output on the 6600 that it has "integrated graphics". Does this mean that it has 2 video cards, or just that it is using the onboard Intel graphics chipset? I'll have to assume that it is simply the Intel graphics as your lspci isn't listing a second 'card'. There are a couple things I'd try;
First when it boots, hit the letter 'e' when you get to Grub and edit it. It should look something like the following;
set root='hd0,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 6b67fed8-816a-4315-89d3-86e3bd6ad4ab
else
search --no-floppy --fs-uuid --set=root 6b67fed8-816a-4315-89d3-86e3bd6ad4ab
fi
echo 'Loading Linux 3.7-trunk-amd64 ...'
linux /boot/vmlinuz-3.7-trunk-amd64 root=UUID=6b67fed8-816a-4315-89d3-86e3bd6ad4ab ro acpi=noirq quiet no splash
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-3.7-trunk-amd64
The stuff highlighted in red can be changed to all manner of things to get it to boot right. On the above example, acpi=noirq and no splash were the additions on mine that made that particular laptop work. "Quiet" was already there. You could also try 'nomodeset'. Thats just a quick couple of ideas off the top of my head. Do a quick google search for "editing grub boot entries" and you'll find a lot to experiment with!
Hope that helps...