Ubuntu 9.04 Dell GX240 Display Dims Randomly

[kilowattradio]

At times when I am running Ubuntu the display in Gnome will randomly dim. Especially when I am running gnome-terminal the most and at other odd times. I did a search and found discussion about power saving settings causing this. Also at times my CPU monitor GUI will say it is at 100% and I ran top command in terminal and the most cpu usage at the same time is 20-40%. Can this display dimming be created by power management or by detection of CPU usage?

Thanks for any help.
:confused:

[kilowattradio]

Here is a screen shot that captured part of the dimming, but not the whole dimming effect was captured in the screenshot.