I have added a stumble upon button to my page but when the stumble upon link is followed back by stumble users it leads back to drunk ducks mainpage and not my page why is this? What can I do to fix it?

I haven't tried Stumbling my own work yet, but I would suggest to try stumbling the picture itself. (go into your comic archive and click on one of the titles and it will show only the comic.) If possible, that may help, but I haven't tried it out yet so no guarantees.

That's because you have an error with your link. Links on DD with errors automatically go to the front page.
Go over the coding carfully and try and make sure it's exactly right with the right link formatting.