Thinking that I would like to see his .bkmslf file, I corresponded with Dr. Steinman on this off-list.  The latest news is that after re-opening the .bkmslf file the next day with the new version 0.9.11, all was OK.

If anyone else sees this issue of multiple copies of bookmarks appearing "suddenly", I'd like to point out that there are a couple ways to get this...

Multiple Bookmarks Created -- Case 1

• Create a Bookmarkshelf with, say three Clients: Camino, Firefox, Opera.
• Export to all three Clients.  Now you've got each item in all three clients.
• The next day or the next week, create a new Bookmarkshelf document with the same three clients, "Combined".  In the New Bookmarkshelf wizard dialogs, do NOT check "Skip bookmarks with same URL".

The new Bookmarkshelf thus created will definitely have three of each bookmark, one each from Camino, Firefox, and Opera.  Because the new Bookmarkshelf hasn't "seen" any of these bookmarks before, it does not know any of their identifiers and therefore does not know that they are exports of the same bookmarks.  And because you did not tell it to skip bookmarks with the same URL, it dutifully creates new items from all of them.

The old Bookmarkshelf will still be around, and will have only one of each, and should not be bothered by the existence, importing or exporting by the new one.

Multiple Bookmarks Created -- Case 2

If, with such a multiple-client Bookmarkshelf, you run some other bookmarks management utility which rewrites your bookmarks file(s) and does not preserve the identifiers, then the next time you import from these Client(s), BookMacster will not recognize these items and will import them as new additions.

Now, this could also happen if, for example, Firefox would decide one day to assign all new identifiers to all of your bookmarks.  I've never seen it do that.  It's possible, maybe if you restored from one of Firefox' built-in backup files.

Thank you, Scott.  I'm unable to reproduce this, although I have had a couple other reports of this problem with earlier versions.  Please set that .bkmslf file aside and try and if you can try and remember as much as you can about what happened.  When you import, I suspect?  Firefox involved?

Jerry