Ok... something NEW is up I think.
This just happened to me today also.
How it happened.
I was trying to play my new copy of THUG2 PAL. It would not boot. I spent quite sometime trying to figure out why not. If it wasn't cracked or something.
Long story short. I tried another game, with an UNSIGNED xbe, and it worked fine.
So I kept thinking it was just that game.
Then I tried my other games, which worked the previous day.
No luck.
I thought my modchip had come loose or something. So I checked that. Everything was fine.
Long story short, either something about the date, or some new bug is happening I think. I have never seen anything like this. Only XBEs that are signed won't work.
In other words, emulators, XBMC, and homebrew games work fine. Just retail games won't boot.
ANY HELP would be great. The Avalaunch IRC channel seems relatively unhelpful, not that they aren't trying, just a rehash of ideas I have already gone through.
Long story short, it isn't the chip, it isn't the bios, it isn't that Avalaunch needs to be reinstalled. I tried all those. The fact it was working yesterday just fine makes me think something must have gotten changed without my knowledge.