I've looked at your other thread
www.sourcecoast.com/forums/jfbconnect/jf...profile-image-upload and one off-the-wall guess is that maybe the following statement was deleting the temporary avatar image that JFBConnect was using in the /tmp/scprofile_USERID_pic_tmp.jpg file. If you encounter the problem again, that'd be one thing to check.
$handle = new Upload($file['image']);
But that is a complete guess since I am unaware of where in K2 you're making your changes. Obviously, let us know if you see any other strange behavior....
-Melissa