Well, Still working, no problems, like the very first day I got it. I wouldn't sell it on ebay, it's working fine since my post. And I wouldn't like to "screw" someone else knowing it might happen again.
I've played several games, to test it, the alone in the dark demo,...everything is like that YLOD thingy never happened. I've turned it on and off more than ten times, of course not in a row, and no problems.
Knocks on wood!
I will indeed do a backup!
I'd like to note that on thursday evening, the 30th, I've left the PS3 on all night to download the new demos from de PSN store. On friday 31st in the morning, I installed all the demos but the one I wanted to most, Mirror Edge woud not install and got the error message. Can't recall the number written. So I deleted it, and proceed to download it again before going to work. (I still haven't turned it off since thursday Evening.)
So at noon, for lunch, I get back home, download is done and I try to install it and still doesn't work. Again that error, ironcly, the demo I wanted the most to try out.
Then I turned it off because I though I left the PS3 on way too long. I didn't have time to play that night because I went out, our band was playing live in a bar.
So this saturday morning, the YLOD happened.
I think I had to share that. In all, I meant to say that I left my PS3 on for more 15 hours. Not saying that the YLOD is because of that but it might have to do with it. Not sure.