Recently I inherited laptop and most of the things I do I do on this laptop. I have a desktop PC that is much more powerful and most of the applications I run on this desktop machine e.g. GIMP, VirtualBox and VMs and more. I do connect to my desktop Ubuntu machine from my laptop (ssh), and run remote applications on my laptop (X11 forwarding). Everything works quite nice. But... I have had some issues to synchronise files (enabled for UbuntuOne synchronisation within ~/home/<user>) from my desktop to UbuntuOne cloud. It works fine when I log in to desktop but not when I do ssh to it. For example I do ssh to my Ubuntu desktop, edit some file (vim test.txt) that is in the folder that is synchronising to UbuntuOne cloud, save changes and ... nothing - new version is not pushed into UbuntuOne server automatically. It is annoying and I could stand it - there are ways to overcome this issue e.g. login into desktop machine but I knew that there is some problem that needs to be tracked and corrected.
After a few hours of searching and trying I found the answer (almost).