What I do in this case is:

Suppose you have 4 computers ok (a notebook, and computers One, Two and Three). Than you travel for a month, using only your notebook. You got your notebook a lot of new bookmarks and passwords. It is too much different from the other 3 computers, then this (I guess) is the cause of firefox-sync (fc) confusion.

When you get home and turn on computer One, hoping sync will do the job, you get a lot of duplicates.

Now, to make it worst, the server also update itself to the duplicated set.

If you don't notice and turn on also computer Two and Three, you have all of them messed up. Your only hope is your local database stored in your notebook. If you lost this also, you must clean it manually.

But if you was clever enogh to stop the bleeding before the notebook (and hopefully before computer Two and Three also, so you just need to correct computer One), all you need to do is:

Step One: The Upload. Correcting the server data!

Using the computer you know is up to date, i.e., the notebook.

1- Turn on your notebook. Wait till the boot and all that little icons are completely loaded, so you have a fast computer to act. 2- Click on the Firefox icon. 3- BEFORE the sync start taking action to mess up also your notebook, go fast to: (Do it all at once, in a single breath! I recommend you practice in some other computer before you try for real)

menu Tools / Sync / Preferences / Manage account / Reset Sync / -> Replace all other devices with this computer's data / next / Yes!

This will make the data on your notebook to be uploaded to the server, correcting it.

Now Step Two: The Download. Correcting the duplicated computer.

Again you need to be fast, before sync starts to mess up. But now, you will turn on the computer One, the one that has duplicated data.

Do exact the same steps but:

-> Replace all data on this computer with my Sync data

This will download the Sync Server data to your computer, without merging it with the local data. Merging is the problem that creates duplicated data.

Do the Step 2 in all duplicated computers you have. If you are not fast enough and sync merge again, you need to do step one again.

If you are slow in step one, and lose the original data, you need to clean manually.

I hope this helps a lots of people.

I also hope that the developers who read this do one of the two: 1- Tell me I'm doing a lot of work for there is another fast way to solve this problem, or 2- implement another fast way to solve this problem.

Thanks! Beco

This is an update to beco's response on Firefox’s website, since my command string did not match what was shown there I have shown the updated command string and did some minor editing within the instructions.

Perhaps the original command string matched the FFV4 beta version?

Suppose you have 4 computers… ok (a notebook, and computers One, Two and Three). Then you travel for a month, using only your notebook. During your journey, you have added a lot of new bookmarks to your notebook. It is now much different from the other 3 computers, then this (I guess) you could call is a cause of firefox-sync (fc) confusion.

When you get home and turn on computer One, hoping sync will do the job, you get a lot of duplicates.

Now, to make it worse, the server also updates itself to the duplicated set.

If you don't notice the problem right away, and turn on computers Two and Three, you now have all three of them messed up. Your only hope is contained the local database stored in your notebook. If you lost this also, you must clean it manually.

But if you were clever enough to stop the bleeding before the notebook (and hopefully before computers Two and Three, so you just need to correct the bookmarks on computer One),

This is the process to fix:

Step One: The Upload. You need to correct the server data FIRST!

Using the computer you know is up to date, i.e., the notebook.

1- Turn on your notebook. Wait till the boot and all the little icons are completely loaded, so you have a computer that can respond quickly to your commands.

2- Click on the Firefox icon.

3- BEFORE the sync starts taking any action that could mess up your notebook, go fast to: (The original author was concerned that this had to be done right away. I did not find that it had to be accomplished in the first few seconds of logging in. However, within the first minute IS appropriate… He said-->Do it all at once, in a single breath! I recommend you practice in some other computer before you try for real)

'''Also Remember... The ALT key will display Firefox 4’s Command Menu on Windows7 PCs.

Revised Command String... Menu: Tools / Options / Sync / Manage Account> / Reset Sync /  Replace all other devices with this computer's data / Next / Next! ''''

This will make the data on your notebook to be uploaded to the server, correcting it.

'''Now Step Two''': '''The Download. Correcting the duplicated computer.

Again you need to be fast, before sync starts to mess up.

Now, turn on the computer One, the one that has duplicated data.

Do exact the same steps as in Step 1... but this time select....  Replace all data on this computer with my Sync data  I did this and it seemed to fix the problem.

All the Bookmarks on both my second PC as well as the Firefox APP on my iPhone were updated without duplication.

This will download the Sync Server data to your computer, without merging it with the local data. Merging is the problem that creates duplicated data.

Do Step 2 in any other duplicated computers that need repair.

If you are not fast enough, the original author says that sync will merge again. If that happens… just repeat as needed.

I too hope this helps somebody else and that the FF4 developers fix the Merge issue,

- BobDi

Thanks, This helped...