Has anyone else noticed weird behavior with background apps preventing their iphone4 from auto dimming? I noticed that my phone was not auto dimming and brightness was always cranked up. So I restored the settings to default and it fixed the problem. Then a couple of days later I notice auto dimming is not working again. The phone stays on the same brightness until the screen auto locks. A reboot does not clear it. However shutting off all background apps does fix the problem. I kill all the running apps and just like magic the auto dim is working again. Seems to be some weird ios4 thing with the background apps.