So I recently purchased a T Mobile Blackberry Pearl 8100 and unlocked it to use it with another carrier. But to the matter of fact, it reboots every now and then. I installed the OS once again but didnt work out. Currently i am having 4.2.1.107. I tried upgrading it to 4.5 but that didnt work out. At the end when it connects to the device it gave some error and said i will have to enter password on the handset which had just a while screen. So had to again install 4.2.1.107. The problem still persists. I tried formating my media card, but that didnt bring any joy. Please help guys. I am stuck with this phone and this problem.