I have been noticing a lot of people may not understand how commenting back to someone works.  Im seeing a lot of people leave comments for themselves when someone has left a comment for them and the other person may not realize they question/comment was answered.

When someone leaves a comment on your page,  and you want to comment back, dont clicke the leave comment link above where the comments are, you need to click the green arrow in the comment that was left for you... like this:

that way the comment will be left on your friends page...not your own and they will know you respeonded :)