I just want to report inconsistencies in synchronizing 4 machines. ALL four were introduced to syncing in the last week or so under the latest Firefox. No account was open under the older sync method. 3 machines below run Firefox 33.0. The Windows XP machine runs Firefox 32. Two Win 8.1 PCs sync well between each other (can see each other's tabs and bookmarks). A Win7 Starter Edition PC syncs nothing in & out, even though the Sync icon turns when clicked on. A WinXP PC communicates its bookmarks and bookmark folders to the Win8 PCs, but NOT its tabs. After the commands HISTORY | TABS FROM OTHER DEVICES in the Win8 PCs, no tab from the XP computer shows up, even though the XP computer has open active tabs.