Ok guys, I'm the guy that does the gNatty Gnome respin, I use UCK but my early versions I used the updated 3.0 gdm, it just didn't work right. You need to force a downgrade to the last 2.32 gdm, everything works fine, doesn't affect Unity or Gnome in any adverse way. Matter of fact gdm 3.0 introduces a path bug that shows itself when you try to launch some games such as gbrainy, probably others.
Ok guys, I'm the guy that does the gNatty Gnome respin, I use UCK but my early versions I used the updated 3.0 gdm, it just didn't work right. You need to force a downgrade to the last 2.32 gdm, everything works fine, doesn't affect Unity or Gnome in any adverse way. Matter of fact gdm 3.0 introduces a path bug that shows itself when you try to launch some games such as gbrainy, probably others.
What app are you using to build your iso?