Bug#744075: bbswitch-dkms: fails to turn off discrete video card

[Dmitriy]

Package: bbswitch-dkms
Version: 0.8-1~bpo70+1
Severity: important

Dear Maintainer,

I have platform with i915 (Celeron 1037U) and nvidia 705m. I wish to disable discrete video, so i installed bbswitch.
After "echo OFF > /proc/acpi/bbswitch" the status is still "ON". Dmesg shows "bbswitch: disabling discrete graphics" with no errors.
What additional information do I need to send you to solve this problem?

-- System Information:
Debian Release: 7.4
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.2.0-4-amd64 (SMP w/2 CPU cores)
Locale: LANG=ru_RU.UTF-8, LC_CTYPE=ru_RU.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages bbswitch-dkms depends on:
ii  dkms  2.2.0.3-1.2

bbswitch-dkms recommends no packages.

Versions of packages bbswitch-dkms suggests:
pn  bumblebee  <none>

-- no debconf information