I have an old monitor, bought in 1990, 640x480 @ 70 Hz.
With Slackware 13.37 default configuration it gets the wrong mode during boot.
Adding:
append="video=VGA-1:640x480@66"
to "/etc/lilo.conf" fixes that.
>66" and "62" work, "70" not...
I got "VGA-1" from dmesg:
[ 11.465128] [drm] nouveau 0000:00:05.0: Output VGA-1 is running on CRTC 0 using output B

Brute force also helps:
mv -i /lib/modules/2.6.37.6-smp/kernel/drivers/gpu/drm/nouveau/ /lib/modules/2.6.37.6-smp/kernel/drivers/gpu/drm/__nouveau/

2011-05-13