When building a new profile on Digg, do not immediately add friends, especially power users.
When you add someone on Digg, they are notified that they have a new fan. People tend to have a lot of fans and power users literally thousands.
That means you have only one shot to friend someone and have them friend you back before you become lost in the mix and never seen again.
If your account show little or no activity, or history, people are likely to skip adding you as a friend.
So instead of jumping right into the act of friending, spend some time digging, commenting, and submitting a few good stories.
If you already made the above mistake, then unfriend the people who did not add you and add them again when your account is a little more mature.