Recently I upgraded to OS.519 and yesterday, I took my phone out of my pocket to find the screen was blank with the message "Technical Issue Please return to place of purchase for repair." I was wondering if anyone else has been having this issue. I have downgraded OSs and tried to upgrade back to OS 5 and get that message everytime I upgrade, wheter it is OTA or from desktop manager. I have only installed apps from the blackberry app store, namely a golf gps system, gwabbit and pandora. Is there another version of OS 5 that I can use? I really like the sms threading that it did.