Comment 7 for bug 761578

Same thing here on raring.

shankao@maldita:~/www/aftertime$ sudo sysctl fs.inotify.max_user_watches
fs.inotify.max_user_watches = 8192

And it affects other programs of the system (i.e. tail reverts to polling).

I suggest to either increase the value automatically when installing ubuntuone to accomodate its requirements, decrease these requirements or, at least, notify the users somehow of the situation and the workarounds that they can try.