Hi,
I noticed an issue: when the category of a post is modified before posting a post on the blog (so the permalink also change), the update on twitter is without the link (on fb is fine).
EG: http://img829.imageshack.us/img829/17/20120711021433pm.png
Bye
http://wordpress.org/extend/plugins/social-networks-auto-poster-facebook-twitter-g/
