WP loop Problem

From yesterday if i click on “ADD…” page will go in a loop…

Example Url:
http://www.nextdoormodel.com/christmas-countdown-faith-picozzi-xmas/?wpfpaction=add&postid=6261

if i remove POST NAME from URL all work great
example: http://www.nextdoormodel.com/?wpfpaction=add&postid=6261

Sorry for my bad english…
How could i fix it?
thanks

http://ww.wp.xz.cn/plugins/wp-favorite-posts/