I have an Iphone 8gb 1.1.1 OTB upgraded to 1.1.4 and unlocked with Ziphone.

It used to work fine, had some freezing problems fixed with autobright off and never lock.

However now I have a starger problem. Without any particular reason or app use the iphone when on standby (screen turned off by pressing power button) it crashes as when I go to swtich the screen back on to use it, it odes not turn on so I have to restart the iphone (power + home). There is no specific timing for it to happen the iphone could be ok for 2 days then have the problem 3 times in a day.

Thanks in advance for any help you may provide