EN X6 sync problem


I am having problems with the sync function in X6.  It appears to sync from EndNote Web to my desktop only - when I sync it will delete the citations on my desktop (because there are no citations on EndNote Web).  I can import citations to EndNote web, and presumably then sync, but then all of the groups are missing and I have the same problem if I make changes/additions on the desktop EN.  Any suggestions?

I think the problem arose because I deleted the citations on endnote web after the first sync while I was trying to figure out the sync function - now I have no way of starting afresh.