Unfortunately, BookMacster 1.10 was posted for a short time with a bug that causes failure to import Delicious, Diigo, or Pinboard bookmarks if new items are present.  If you have this issue, please update to BookMacster version 1.10.1 by setting your preference to get Alpha versions as described here:

http://www.sheepsystems.com/files/support_articles/bkmx-get-beta.html

After you have updated to BookMacster 1.10.1, you may change the update preference checkboxes back to whatever they were before, if desired.