The only reason I disable the gsm option when I am at work is because reception for me is so poor that it is worthless to keep it on. I am not sure about Exchange as I do not use it. Maybe you're right that is the culprit of your battery issues. All I was doing was offering you an example, ie. My battery usage profile. I would definitely like it if the N900 had better battery life, but for my use, and considering I have USB in my car as well, I end up being able to charge the device any time I need, so it is not really an issue for me.