yup, checked that the first time I tried to figure this out . . . but you just gave me an idea, hold on . . . nope: the grayed-out sleep time is set to 12:00am, and I was wondering if that was "Cupertino time" and putting my Air to sleep somehow, but my (I think) the times I get that message have not been at 12:00 Cupertino time . . .
I'll try to diagnose: I THINK it only happens when I'm connected to the internet. I've seen similar posts on other forums, but I'm committed to figuring this out here. Will keep you (all?) updated.
Thanks Nicky . .
Don