Well, turns out this problem seems to be more with gnome/gdm than with the video driver.
I logged in from gdm with the VGA unplugged, which puts the LVDS on crtc 0. Then plugged in the VGA and turned it on with xrandr, set up the frequencies, etc. with xrandr. Then used gnome's Screen tool to "apply" the current settings. Not sure where it saves them to, but I had to do this for both of the computer's users. After this, everything works fine. And the LVDS is always assigned to crtc 0 even with the VGA plugged in when X/gnome starts. Have no idea how/why gnome was forcing VGA-0 to crtc 0 originally. Not sure if this should be re-assigned to some gnome package. Apologize for the false alarm here. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org