This was supposed to be the year of the iPad's crowning triumph in education--its adoption by and distribution throughout the nation's second-largest school district, Los Angeles. Events haven't quite turned out as planned.A $1 billion iPad-distribution program that started in the fall has run up against a series of obstacles. Students hacked their way past the tablet's security; parents raised concerns that they were liable for iPad damage; and the program ran into cost overruns. Put all that together and the result is that officials recalled the iPads while they rethink their plan. Reportedly, the conflict even put Superintendent John Deasy's job in jeopardy at one point."It's an ambitious project, involving lots of money, so there were probably going to be some problems coming out of the gate," said Michael Janofsky, managing editor of L.A