I just downloaded and installed the mobile security app from amazon.com., I own a kindle fire, and when I tried ti install the anti theft feature, I was notified that there were two different signatures; both had to be entered under the same key. I am not certain what this means. I cannot use either the firewall or the anti theft feature. I have used avast for my personal computer, and have been very satisfied with the product. Why sm I having this problem? Iz the mobile security product really compatible with the kindle? Your assistance would be greatly appreciated. Thank you.