I use the first generation of iPad. I upgraded the os to 4.3.3 through itunes. After that, any of the apps I obtained from apps store will simply crash whenever I try to launch it. I don't jailbreak the device, and every app I have downloaded is from the official store. People tell me to reboot it by holding the top and bottom buttons at the same time. I have tried for a few times, but everything remains the same. I don't know why. I am so regretful now! Anyone could help? Thanks.