I'm using a build that was generated today (8/29/13).
Here's what happened:
1. I did a fresh install of Sync.
2. Setup it to point to in.liferay.com, it started Syncing and downloading all files from my sites.
3. When there was 194 files left to finish, I closed my macbook and came home.
4. Some hours later I opened my macbook again.
5. Sync got stuck on 194 files and never downloaded the rest of the files.
6. Restarting Sync made it work again and all files were downloaded.
Looks like it wasn't able to recover the Syncing process when my computer was online again.
As you can see in the logs, I got lots of these:
29 Aug 2013 16:49:09,630 DEBUG [BaseEvent:171] Timeout waiting for connection from pool
29 Aug 2013 16:49:09,630 DEBUG [RetryQueue:34] Adding failed event 1 -> class com.liferay.sync.modules.documentlibrary.server.remote.event.GetFileEntriesEvent
29 Aug 2013 16:49:24,639 DEBUG [BaseEvent:171] Timeout waiting for connection from pool
29 Aug 2013 16:49:24,639 DEBUG [RetryQueue:34] Adding failed event 1 -> class com.liferay.sync.modules.documentlibrary.server.remote.event.GetFoldersEvent