Digg's interface doesn't make me a happy camper.
Not only do you have to go through multiple screens, but you have to review an auto-generated list of current diggs that might be your digg and double-check by hand that your digg hasn't been already submitted.
(Actually, like that feature as I've found some interesting stories that way.)
But it is such a laborious process to get a digg dugg that I am more likely to post to my del.icio.us account rather than post to digg.
I mean, who has time?!?
If digg wants to maintain it's marketshare, it is going to have to improve it's user interface.