OK...here's the deal. I have my iPhone plugged in, and I open iTunes, click the "check for updates" button for the iPhone, and it gives me this alert message: What? Is my iPhone just not able to run iOS4 or am I doing something wrong. It says that 3.1.3 is the current, and I am up-to-date. I have no way to figure out how to update it to iOS4. Somebody please help.