When I run Fedora 16 with a 20 in monitor (as primary) and a 24 in monitor (as secondary), the 20 in monitor will turn off correctly after the pre-set time, however the 24 in monitor will not. I'm using a Quadro FX 570 graphics card with the standard open source Fedora drivers. Both monitors are connected to DVI ports.
If I use identical 20 in monitors there are no power problems. Both monitors switch off correctly.
Has anybody else had this problem?
I can manually disable the 24 in monitor in System Settings, but if I log out, it will automatically be enabled again (probably because of the gdm user settings).
Everything works correctly running the same hardware with Ubuntu 11.10 and the nVidia drivers. I haven't tried Ubuntu with the open source drivers.