Panic.plist constant reboot

Received my iPhone almost a year ago and it has been rebooting on odd occasions. A few months back, it started getting worse, with it rebooting 4 - 6 times in a row, normally whilst on a call. After contacting iStore (here in South Africa), it was suggested to install the IOS as a new phone. Did that without success. I then updated to IOS6 and it still occurred. Recently updated with IOS6.0.1. Still rebooting. Got really sick of this, as it would sometimes reboot twice a day, so I started doing investigations myself. I notices that SIRI also produced a diagnostic report at the same time. I disabled SIRI and now the phone only reboots once (so fa). The diagnostic report show Reset Counter happens at the same time as the Panic.Plist. Any help or suggestions, as iStore again recommends installing as a new phone!!!!