On 05/04/2013 02:01 AM, Paul Davis wrote:
  it appears to be video h/w + driver related, not
ardour related. but hard
 to say. 
Fwiw, I've had issues with nouveau and older nvidia cards:
http://askubuntu.com/questions/232439/lubuntu-12-04-unresponsive-windows-wi…
There is also an X setting that might help:
etc/X11/xorg.conf.d/20-nouveau.conf
Code: Select all
     Section "Device"
         Identifier    "Device 0"
         Driver    "nouveau"
         Option    "ShadowFB"   "true"
     EndSection
     #
Regards,
Jeremy