Created attachment 8603813 [details] Firefox bookmarks after sync. The columns "Added" and "Last Modified" are not synchronized. User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:37.0) Gecko/20100101 Firefox/37.0 Build ID: 20150415140819 Steps to reproduce: I set up Sync on two computers (A and B) with previous bookmarks to synchronize the bookmarks on each computer with the other. Actual results: The bookmarks got synced. However, the columns "Added" and "Last Modified" where not synched. Instead on computer A the original timestamps from computer B where replaced by the current time-stamp and the reverse on computer B with bookmarks from computer A. Expected results: The data in "Added" and "Last Modified" should be identical on both computers, i.e. the original timestamps should be synchronized as I have not edited nor added any bookmarks.
Happens to me too.
I confirm that I can reproduce this behavior on Mozilla Firefox ESR 45.4.0 on Red Hat Enterprise Linux Server release 7.2. I feel that the severity level should be critical as this behavior is a corruption of user data. The Added and Last Modified fields are important metadata for analysis of user bookmarks. The values should consistently represent the times that bookmarks are added and modified by the user, not the times that the synchronization occurred.
I agree that this is both inaccurate and frustrating. Activity Stream is running into this issue, too: it gets confused on a new device (or a device that just hasn't synced in a while) because it sees all synced bookmarks as new. We're using bug 676563 as the product tracking bug, and expect to work on this in the coming months.