I don't know if anyone else has experienced this but this is sure causing me a headache. I'll start by saying that I love the Google Firefox Browser Sync tool. Since I started using it it has made my life immensely easier. The downside to this has been that once in a while I try to synchronize a new computer with the with what I have and it all falls apart. what happens is this, the new computer doesn't get updated to my current settings, instead the current settings get changed to match the newly added computer. This causes me to lose everything that I have worked on for so long. Fortunately I had the foresight to backup my bookmarks before doing this and have since recovered what I lost in the sync. So my lesson and advice to you is do regular backups of your bookmarks and whatever else is important to you because it can all still come crumbling down.