External monitor switching problem on Lenovo Thinkpad X60s

Folks,

Monitor switching does not work on my machine (Thinkpad X60s). The video is Intel 945GM, and I am running kernel 2.6.16 in Fedora Core 5. It is impossible to get a picture on an external monitor. Writing to /proc/acpi/ibm/video has no effect - I would write 'crt_enable' , but it is still shown as disabled:

$cat /proc/acpi/ibm/video

status:         supported
lcd:            enabled
crt:            disabled
dvi:            disabled
auto:           enabled
commands:       lcd_enable, lcd_disable
commands:       crt_enable, crt_disable
commands:       dvi_enable, dvi_disable
commands:       auto_enable, auto_disable
commands:       video_switch, expand_toggle

(video switching hotkey Fn-F7 doesn't work either, although all others do).

dmesg shows there are two video output devices:
ACPI: Video Device [VID] (multi-head: yes rom: no post: no)
ACPI: Video Device [VID] (multi-head: yes rom: no post: no)

and there are two /proc/acpi/video/VID directories. Could this be confusing the kernel? I looked in the decompiled DSDT code and, while I don't understand what it does (not being a developer) I can see that there are two VID devices there (_SB.PCI0.VID and _SB.PCI0.AGP.VID) and it looks like video switching routines are different for the two. This is just my guess, but could this be what causes the problem?

By the way, video switching works fine with IBM DOS v.5 (1991 version).

Could someone shed some light on this issue? I would be happy to provide any additional info, DSDT tables, etc.

Regards,

Vladimir Florinski <[email protected]>