Xmarks on Firefox

[#1]

I have been using Xmarks on Firefox for years, very successfully,... although in the last week it has not been working "properly" at all....  as you know, it synchs (usually) automatically, or at shutdown..... but for the past week it has not been showing on  shutdown that there are updates to bookmarks ... so I assumed it had been done automatically....
Yesterday I went to look for a bookmark I did the night before, but it ( and a few others ) were not listed... so I clicked on the xmarks icon, and it said Synching successfully,.... last synch 6 April 2014...  so I clicked on Synch now... it ran the red bar and reported as before.... last synch 6 April... that was on V 4.21  so have disabled that one, and downloaded the latest.. 4.25 and it still does the same.... ( running Firefox 28.0 )
Any suggestions ?  ( also logged in and out a couple of times, and been through the set up )...

[#2]

you can sync , import/export  bookmarks within FF so why use something else ?

[#3]

Erm....... Cos I do.... !    Just wanted some help to find out why it is doing that,... so I posted a query on here, hoping someone would be able to help.... or then again...........    and... oh yes.... FIrefox won`t have all my bookmarks since 6 april ......... will they  ? ? ? 

[#4]

Xmarks v4.2.1 for Firefox is working fine for me (Mac OS X 10.8.5).  And "Checking for updates" to the add-ons says there are no new updates for it.
If you've tried uninstalling and reinstalling the add-on (quitting Firefox and reloading it between each stage), and had a look on the Xmarks support webpages, then the next thing I'd try is to start Firefox with a new (blank) profile.  Then you can install the Xmarks add-on without any other add-ons or any of your settings etc.  See if it works then.  If it does, then gradually install every other one of your add-ons and themes etc, seeing if the problem re-emerges after each one - maybe there's a conflict?
See
https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
and http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_Windows
about starting Firefox with a different profile.
HTH

[#5]

Thanks for the info... and the linky`s.....
Spoke to a friend of mine on the phone... he said I could download the "server copy" manually in  Xmarks Settings > Advanced > Force Overwrite of local data  then click on "Download" button... It has worked... so am now synching properly again...
Thanks again..