My Intel BlackBook 13" has developed a screen brightness problem after installing 10.6.7 using Software Update. The computer has never been dropped or abused in any way. The screen does not flicker or disappear when changing the viewing angle. The Problem: After the update, when waking from sleep, the screen went black. Over the last few days (after performing all of the customary mac troubleshooting and resets) a pattern has emerged. From a cold start in the morning, everything runs normal but the screen is black. To see the login window I can reset the brightness (F1) and then press the (F2) once and I can see the dimly lit login window enough to login. When at the desktop, if I try the F2 beyond about 3 or 4 presses the screen goes black and I have to reset to zero again and then F2 brings the screen back to the low illumination. As the day goes on I can get the screen to a brighter and brighter level before blacking out again. My screen appears brighter than ever after a few hours but will not hold that max brightness for long until black again. I have 1) reset the PRAM and SMC, 2) Booted from the Original and repaired permissions and HD from Disk Utility 3) ran the Hardware test and 4) researched the problem extensively noting that most screen problems are associated with the MBP rather than the MB. Of course the MB uses integrated graphics unlike the MBP. I'm not sure what prefs I could trash and perhaps someone has some insight into that. Everything appears ok from the tests but the problem persists.