I've been using Firefox for years and never had this significant of an issue in syncing my xMarks/Bookmarks. I have xMarks installed on my home desktop (Windows 7) and my work desktop (iMac, OS X). A couple of weeks ago my bookmarks sync began taking a long time and never completing accurately. I witnessed one of these two results: 1) the sync window would run and after confirming history sync, the bookmarks sync never finished or 2) the sync window would run and indicate that my history and bookmarks were synced (but in fact neither of them were). I experienced this throughout my use of Firefox--1) at the beginning of a firefox browser session, 2) when I would manually try to sync or the xMarks window would ask to sync during a session and also 3) when I was closing out a window. Previously I was able to solve this issue through either: 1) choosing to override my local set of bookmarks with the server set OR 2) restoring a bookmarks set from a few hours or the day before the sync issue occurred. I performed both of these earlier "fixes" through the my xMarks web portal opened in a tab in my Firefox browser. I absolutely love using Firefox as my primary browser. The bookmarks sidebar AND xMarks are two of the primary elements I really value. Any help you can give in solving this issue is greatly appreciated. Thanks!