I assure you that if I had installed a custom ROM or overclocked it I would have said so as that would be very relevant It is the standard TELSTRA unit with the factory OTA upgrade to Froyo The problem existed before and after the upgrade so is not a result of that I am not sure about reliable sources but here are a few links httpandroidforumscomdesiresupporttroubleshootingdesireoverheatingrestartinghtml httpforumxdadeveloperscomshowthreadphpthighlightoverheat httpforumxdadeveloperscomshowthreadphpthighlightreboot httpwwwyoutubecomwatchvKLlQurOc httpwwwyoutubecomwatchvLkWmsZGh