Phone will not let me ENCRYPT I want to encrypt my apps and personal data, such as passwords to email etc.

If I have factory reset my phone (GS2sprint) and it is fully charged (over 90%) and plugged in. So I went to Settings&rarr;Apps&rarr;Security, and from there to Encrypt or Encrypt SDCard -- but it won't let me encrypt: The buttons are grayed out.

Why won't it let me encrypt? I have a new file that I have not seen before which is sprint extention. It will not let me stop it and like I said after Hard Factory reset it still will not let me encrypt anything.
I know I am late to this discussion, but, for others out there that may have not gotten an answer to this yet, device encryption on some devices may only work with a strong password. A (medium security) PIN may not be enough.