I also have this problem. I'm using the latest version of Firefox and every time I try to sync, Firefox locks up. I'm syncing between two computers, both of which have the most recent version of zotero. I've tried resetting (restoring from the server only) on both PCs and the same thing happens every time.

I made backups of my databases on both computers, but I really need zotero's functionality as I have a proposal due very soon. Please help!

Update: zotero did sync after a while. I had a cursory look and everything seemed to be there. Then when I wanted to move an item to my newly created group (very exciting!), I got this error: 1524112728

derxen

I first got an error report, but after retrying it worked.

After many attempts the sync operation finally worked! I did not change any settings and did not do anything special. After half a dozen attempts the sync suddenly just worked.
I use Firefox 3.10 on Ubuntu 9.04 if this is of any use.
I will watch how this develop. Version 1.5 functioned without any problems. From the comments it seems as if several users are experiencing the same problem with Zotero 2. I have backed up my library just in case...

Update: dragging items to the group folder now works as well, at least on this (home, Linux) computer.

derxen

I also use Zotero 2.0b3, just forgot to look it up earlier...

Update: I actually got my databases to work on both of my computers by using the reset feature and just letting them sync (one-at-a time) in firefox. I didn't use firefox at all for web browsing while the sync was being performed since everytime I did, it would lock up. FYI both my PCs run above 3.2 gHz and have more than 2 GB ram so it wasn't a lack of resources that was causing this. Especially since firefox was the only thing locking up - operating systems and other programs still ran fine. FYI I also found that disabling all add-ons had no effect and the sync still failed regardless. It only worked after I used this procedure (all my add-ons were enabled at this time btw)

Procedure I used:

0. Locate your zotero folder and back it up!

(usually it's in your firefox's Profiles folder - in windows go to Run and type %appdata% and then go to Mozilla-->Firefox-->Profiles) Now change the name of your original zotero folder from 'zotero' to something else like 'zotero2' so that firefox will generate a brand new 'zotero' folder

1. Click on the 4th icon from the top left corner of the zotero panel (it looks like a gear)
2. Choose 'Preferences...'
3. Go to the 'Sync' tab (2nd button from the top left corner)
4. Change sub-tabs to 'Reset' (look above the username and password input fields)
5. Choose 'Restore from Zotero Server' and click the 'Reset...' button. You'll get a message saying that firefox has to restart. Let it restart and if you receive a message asking if you'd like to reset the connection, click reset.

IMPORTANT NOTE: After this don't try to open the zotero panel. Zotero is syncing even though the panel is minimized. Every time I tried to open it at this point the sync generally failed and firefox would lock up

6. Don't do anything with firefox for at least an hour ;-)
(Probably depends on the size of your database)

Check to see if everything sync'ed by opening the zotero panel

7. Repeat process on other computers as necessary
8. Rejoice since now you can finish that awful proposal you've been working on

Hope this helps