In AC mode toshiba R500 backlight command toshset trmode -off do not work

[maris]

Binary package hint: toshset

In battery mode till login and after login backlight is off:
# toshset -trmode off
transreflective mode: off
# toshset -trmode on

Backlight goes on and off. Works perfect!

in AC mode:
the same commands,
Backlight is on, so Lcd SCREEN IS DARK AND IMPOSSIBLE to see something!
# toshset -trmode off
DOES NOT WORK!

in AC mode till login:
Backlight is off. So everything is fine.

seems that it is a bug!

I have thread in Ubuntu forum here!
http://ubuntuforums.org/showthread.php?t=1306321
impossible to work with pc - dark screen!
using Toshiba Portege R500 - 11z
Model nr. PPR50E-04X048EN
Ubuntu 9.10

ProblemType: Bug
Architecture: i386
Date: Sat Oct 31 15:02:30 2009
DistroRelease: Ubuntu 9.10
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
Package: toshset 1.75-1
ProcEnviron:
 LANG=lv_LV.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: toshset
Uname: Linux 2.6.31-14-generic i686