Zotero Sync - Dropbox
I have been using Dropbox to sync my entire Zotero folder without problems. This means my library is backed-up online, and I can have it available across different computers if I install Dropbox (cross-platform).
Dropbox currently offers free 2GB accounts. If you follow the link below you get 250MB extra (and I do, too, for referring you).
https://www.getdropbox.com/referrals/NTExNjc1Mjk
After installing Dropbox, you need to open Zotero Preferences > Advanced and change the Zotero folder to a folder you have created in your Dropbox (you should probably name it "Zotero"). You will then have to restart Firefox. Don't forget to copy the contents of your current Zotero folder (located by default in your Firefox profile) to the new location, and everything will be there when you restart Firefox.
Dropbox currently offers free 2GB accounts. If you follow the link below you get 250MB extra (and I do, too, for referring you).
https://www.getdropbox.com/referrals/NTExNjc1Mjk
After installing Dropbox, you need to open Zotero Preferences > Advanced and change the Zotero folder to a folder you have created in your Dropbox (you should probably name it "Zotero"). You will then have to restart Firefox. Don't forget to copy the contents of your current Zotero folder (located by default in your Firefox profile) to the new location, and everything will be there when you restart Firefox.
http://forums.zotero.org/discussion/4115/do-your-backups/?Focus=30344#Comment_30344
http://forums.zotero.org/discussion/5951/cant-sync-with-mydiskse-secure-webdav/?Focus=28619#Comment_28619
http://forums.zotero.org/discussion/5527/export-to-another-computer/?Focus=27644#Comment_27644