I've got a 3G iphone that I unlocked with redsn0w. I've used it for a few days, worked great with the Tmobile SIM etc. Today, I tried to install a program through cydia, something to enable MMS messaging...after it supposedly installed, the phone rebooted and has been in a constant loop of the apple logo screen- it just sits there for a few minutes, then will reboot. I ran redsn0w again to try and restore the unlocked/jailbroken image, redsn0w loads everything fine, I can see all the correct pineapple screens, etc when you are loading the jailbreak software. Then it goes back to the apple logo reboot loop. I'm not sure what to do, please help!!