I have the same issue. I have to reset everything just to get it back, only to have it happen time and time again. this is such a pain as my hubby has trouble with it and can't re enter all the info over and over.
Do you perhaps have a Samsung tv? I'm checking out this with the service center tomorrow. the itv works for youtube and everything just not netflix or itunes movie menu. I think the samsung tv needs an update firmware. but I'll let you know tomorrow.
I really don't tink it's the iTV box. Apple usually makes awesome products. so I'm checking out other possibilities. check back again tomorrow.