I'm using Ubuntu Studio 8.04 with latest updates, and just got a second monitor to plug in to the DVI-D on my Asus M2A-VM motherboard's integrated graphics card, in addition to my old one which is in the VGA, using envyng as recommended by http://www.youtube.com/watch?v=zFX5UssUgcs . It was all working until I added two more sticks of ram, increasing from 2GB to 6GB DDR2-800, at which point it did not go to the login screen, but instead to the black screen of death. I've tried the recovery mode 'fix X server', to no avail, though the computer seems to boot fine until this point. I am using kernel 2.6.24-23, and when I use grub to load an earlier kernel on UbuntuStudio or Linspire 6 at boot, it drops the dual monitor setup and boots fine otherwise. If I remove the newly installed RAM, it will return to booting properly with both monitors. I tried a fresh install of UbuntuStudio with no updates, etc., but installed envyng, and it fails the same.

Here's the /var/log/messages of the failed boot:
http://gw7.no-ip.com/fail.txt

And the successful boot:
http://gw7.no-ip.com/success.txt

The lspci video looks like this:

Perhaps post 5 on http://ubuntuforums.org/showthread.php?t=1053359 might shed some light?