happened to me last night for first time
glitchin wi ma Bro then whole thing shut down staight back to blue wavey lines as it reads hdd then signed in ???????
dont think overheating as got cooler on mine and in an area of its own
Its probably the custom ps3 firmware users of 2.41. It probably conflicts with them causing you to boot to the xmb. I was booted to the XMB before the update of 2.4 or 2.41, so that may be the reason.