Change can stoke conflicted emotions in a computer user. There’s the thrill of the new. Then there’s the dread of problems that may erupt when the old meets the new. Admittedly, I felt those qualms when I prepared to upgrade my iPad to the latest version of its operating system, iOS 4.2. As it turns out, my fears were unnecessary. At first I was hesitant to upgrade on the first day the new version was available. Typically, the pent-up demand for something that’s received the volume of ink and electrons that this edition of iOS has garnered swamps a company’s servers.