I couldn't reply to this message on the forum, so I will write this here.
I am having the same problem as Jim:
but I have a Galaxy Mini. After setting my phone as 'not missing' my phone resets itself to missing, and spamming me with reports. What extra information can I provide to help you solve this problem?
I think that you are on wrong issue tracker and you should have reported this at https://github.com/prey/prey-android-client/issues .
@Mkaysi is right. I think the cause for this is Active SIM detection feature. For more information take a look at this article on our knowledge base.