Coincidentally, I have found a methodology for OP to save his/her posts to avoid to be deleted.
Whenever the OP find his/her post(not answered) have 1 or 2 votes of deletion, then do
delete the post;
undelete the post.
Warning: Do not leave or refresh when the post is deleted.
If everything goes well, the votes of deletion will come back to 0...
Is it legal? Or a bug?