Lately my phone has been locking up from time to time. I originally upgraded to 1.1.1, on an AT&T sim, never having jailbroken the phone. At that point I realized I wanted to try 3rd party apps, so I downgraded to 1.0.2, tried the apps out for a day, then went back to 1.1.1 Since upgrading, there have been two instances that my "slide to unlock" screen has frozen up, and random button presses of Home and Power would take me to my iPod, or turn my display off. I was able to hold down power and get the "slide to power off" screen, but the slider was frozen. The only way to get back to normal was to hold home and power, and reset the phone. Anyone having similar issues? Could the 3rd party apps have cause damage, or perhaps downgrading to 1.0.2? Or am I just paranoid, and this happens to everyone's iPhone from time to time. Thanks.