HP dm3t Laptop Brightness Adjustment

[Brian Hanks]

I recently got a new laptop, an HP dm3t (Core i3-380UM+Intel HD 
Graphics).  It's a great machine except that I am not able to adjust the 
screen brightness in Fedora 14 x86_64.   The Fn keys are recognized, the 
brightness pop-up indicates that an adjustment has been requested, but 
the screen remains on the brightest setting.   I've also validated the 
brightness values in /sys/class/backlight/acpi_video0 are being 
adjusted.  It just seems that they aren't being recognized.

I've tried to pass the following acpi kernel params, but the attempts 
have failed, causing the Fn keys and adjustments to stop working:
acpi_osi=Linux
acpi_backlight=vendor

Any thoughts on what I should try next?

Thanks,
-Brian