My Tecra R840 shows the exact symptoms as described before. I'm on
precise with all current updates (Linux brahms 3.2.0-20-generic
#32-Ubuntu SMP Thu Mar 22 02:22:46 UTC 2012 x86_64 x86_64 x86_64
GNU/Linux).

With and without Seth' patched driver from #8 (Thanks, Seth, for your
fine work. I already appreciated your alps patch while on oneiric.) I'm
able to manipulate the brightness files of all three interfaces under
/sys/class/backlight (acpi_video0, intel_backlight, toshiba). Before
suspend the display respects all these changes and sets the brightness
accordingly. After resume changes in acpi_video0 and toshiba are
ignored, changes in intel_backlight still effectively change the
brightness of the display. This is what I currently use as workaround by
means of the little script attached, which translates the different
values of intel_backlight and acpi_video0/toshiba.

With Seth' driver installed my Tecra freezes on suspend or the backlight
stays off on resume. Before suspend I recognized that changing the
brightness via Fn-F6/7 uses all 8 levels, whereas without the patched
driver one keystroke always takes two at a time. AFAICT the logs don't
give any hint.

** Attachment added: "Workaround script, sets brightness after resume"
   
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/935778/+attachment/2925132/+files/set_brightness

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https://bugs.launchpad.net/bugs/935778

Title:
  Toshiba R840 - brightness controls work on first boot, but do nothing
  after suspend/resume

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