I have a 3GS new bootroom 4.2.1 BB 6.15.00 jailbreaked with redsn0w, unlocked with ultrasn0w but everytime I want to reboot im stuck at apple logo and my phone can not reboot itself. I have to use boot tethered from redsn0w everytime i need to reboot. Is there any way to fix this problem? please help thanks.