Fn key not working properly in Dell Inspiron 1420 with Ubuntu 8.04
 

In Dell 1420 Laptop, Fn + up arrow/down arrow increases or decreases the display brightness level step-by-step. One step for one pressing.

After I installed Ubuntu 8.04; I found that once I press the keys one time, the brightness level change by more than one step. Like 3 or 4 times a time. So, I am not possible to adjust the brightness satisfyingly.

Help me solve this problem.

I have the same problem using a Lenovo T60 and I didn't have this issue with 7.10. I'm not sure why it does that but I've just kind of accepted it and I use the sound icon to change volume.