Ah, found the answer at http://forum.bittorrent.com/topic/19228-latest-sync-build-1112/. Where it says: "Please note that 1.1.x builds are not compatible with 1.0.x builds. You will need to upgrade all devices. We are changing protocol to support mobile devices and doing some optimization to it." That was exactly the issue with me. All my other devices except this one ubuntu machine are still on previous build. So, I guess it's best to wait 'till windows clients get updates and update the rest of the linux machines only after. Many thanks for your work tuxpoldo, and sorry for spamming this thread.
