Craig Christensen's dashboard

I noticed the same issue with trying to drag the scrollbar. It appears that if you have an address selected the selection reached all the way to the right where the scrollbar is and thats why the drag/drop action occurs. You can easily easily work around this by selecting the first entry, then Hold Shift+Page Down to select all the entries.

I do agree that a Delete All button would be handy or even an option to skip entries on import if already in the address book.