Tweetbutton stripped from display suite

After I installed display suite and make some node field arrangements through DS, the tweetbutton disappeared.
After searching the code of tweetbutton, it seems that the button is added through nodeapi and appended/prepended to the node.
And this should be the reason why DS strip away our tweetbutton. I am still a Drupal newbie, and don't know how to add tweetbutton through the hook_link().

Anyone can help to apply a patch for this purpose??

Cheers