Try restoring a bookmark backup from the day before that happened, Firefox keeps 10 days of the automatic bookmarks backups.

See this - https://support.mozilla.org/en-US/kb/Backing-up-restoring-bookmarks#w_restoring-from-backups

Hey! I can't believe someone answered my question so promptly, and your proposed solution solved my problem! Thank you!!!

If I would like to try this sync action again, how do I ensure that my desktop is the master and the mobile device is the slave? For some reason when I checked the Sync settings, this isn't the "recommended" option - why not?

What if I have new bookmarks on the mobile device that I want added to the "master"? Can I set Sync to ask me?

I'd prefer more control over Syncing - ie not on all the time, and have a chance to look over what exactly is being synced, and to what, before electing to proceed. Is there a way to micromanage Sync until I understand it a little better?

Thanks!

The developers have managed to remove the little bit of user control that Sync used to have. Their concept is that it run seamlessly in the background and not require the user to do anything. Really, the only control the user has is which types of data are sent to or received from the sync server, and changing the Data Quota. Basically the sync server is the "master" and the devices the "slaves".

https://support.mozilla.org/en-US/kb/how-do-i-manage-my-firefox-sync-account

You can turn off that autoconnect run of Sync with - services.sync.autoconnect - set to false in about:config, but that's all I have found for "user control". Just move the Sync button from the Customize Palette so you can sync manually at will.

When you say "mobile device", I trust that is an Android device running a Friefox browser, and not an iOS device with the FirefoxHome app, because with FirefoxHome the sync is one way to the mobile device and not from it back to the sync server.

See this SUMO search for support articles about Sync. I still don't have the "big picture" grasp of Sync any longer what with the changes 14 months ago and my loss of interest is using it myself.

I had started writing a Sync user guide that was from a users perspective rather than from a developers view point, that I was planning on posting to my own website, in the fall of 2010 when Firefox 4.0 looked to be in the final Beta stages, but there was a major change made to Sync early in December and since Firefox 4.0 was postponed so often I never got around to finishing that user guide.

To be honest, I really lost interest in using Sync myself with the changes that were made. IMO, they broke what was working fine to make it more "mindless" and automatic, when they should have worked on implementing new features like add-ons sync which is just about ready for release now. And now with all the Sync articles in the KB, I just can't see duplicating most of what's in the KB to tie it all together.

Hi the-edmeister, Thank you again for your informative and helpful reply. I guess if I wanted to relinquish total control over my computer and become a drone, I'd have a Mac! LOL

From your comments I guess I'll either opt for occasional manual sync, or I'll export the bookmarks from my desktop and import them to my device, as I don't want anything automatic going on without my consent. Too often this results in critical data becoming lost.

Yes, I am running Firefox on my Samsung Galxy S2.

Thank you for your additional information, I'll checkout those links.

Best Regards, Kirsten