I just tried the Huge-IT share plugin for wordpress and realized that the twitter share button seems to have a bug: When sharing, the tweet will not link back to the URL. Not cool :-/
changed the file (via edit plugin):
case 'share_twitter_button': $link= 'https://twitter.com/intent/tweet?url=http%3A%2F%2F'.$linkthispage.'&text='.$str;
Now the URL is prepended with http and thus displayed in the twitter share-dialog as well. Mission accomplished.
(And Huge-IT is also informed about the bug + fix)
Have fun and a happy new year