After having the "did not wake from sleep" issue which I thought was fixed by the firmware update, I got the 'does not go to sleep" issue. After talking to AppleCare they had me do a PRAM but the next day the issue recurred. They advised me to take it to a local Apple store, This morning the "does not wake from sleep" issue raised it's head again so I went to the Apple store where the Genius Bar expert consulted with his manager and they agreed right off the bat to replace it with a new computer. I have to pick it up tomorrow after they transfer all of my information to the new MBA. I guess this issue has not yet been resolved with firmware updates but is obviously a hardware issue (well in my case it is).