IPhone 4S doesn't turn on/off Wi-Fi?

I got my iPhone 4S recently. All of a sudden, my iPhone doesn't turn on. I keep pressing the home and power button, but it doesn't power on until I hold both buttons (reboot). Once it finally turns on, the Wi-Fi button is shaded. It says that it's off and I'm not able to turn on the Wi-Fi. I have to reboot the device again for it to work. How come this happens? What can I do to fix it?

Exact same thing happened to my iPhone 4S. It is a glitch in the new software update. I called the store and they scheduled an appointment to see what was causing this- whether it was a software or system flaw. Once they examined my phone, they concluded that it was the software's fault (their fault) for causing my iPhone's Wi-Fi on-off to permanently be shaded off. They provided me with a new refurbished iPhone 4S and backed up all my data onto it so it was just like my old phone. Hope this helps and good luck!