User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:5.0) Gecko/20100101 Firefox/5.0 Build Identifier: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:5.0) Gecko/20100101 Firefox/5.0 I began to use Firefox Sync extension on my iMac on Firefox 3.6 (but it never worked). After I used Firefox 4 beta and Firefox 4 with the same problem (unknow error). Few weeks ago I have succed to use Firefox Sync on my Macbook and on my iPhone with Firefox Home. I have uninstall Firefox on the Imac and install Firefox 5 on it, but synchonization still doesn't work : when I past my sync key spinner appers, disappers and then... nothing Reproducible: Always Steps to Reproduce: 1.Choose "Configure Firefox Sync" in preferences menu 2.Set ID and password, choose Firefox Sync server 3.Paste my synchronization key 4. click on "Continue" button Actual Results: Spinner appers, disappers and then... nothing. Expected Results: Imac should be synchronized on my Firefox Sync account

I precise that I have already tried to reset my account

Do you have FIPS mode enabled on the iMac? If not, what add-ons are you using on the iMac?

Do you know that you are genius ? FIPS was effectively enabled for NSS Internal PKCS #11 Module in Preferences -> Encryption -> Security Devices. I have just disabled FIPS and it works now. Thanks for your help.

Yay!