As far as I was able to test this bug, the locale change is required for ubuntuone-client-applet (OAuth module), not syncdaemon.
Syncdaemon is able to sync files with tr_TR locale.
Open gnome-session-properties, select "Ubuntu One" entry, Edit it and prefix the available command with env LC_ALL=en_US.UTF-8, so that Command (Komut) is
env LC_ALL=en_US.UTF-8 ubuntuone-client-applet
The client will be started with English/USA locale on next login. This is still a workaround but at least it will not require manual syncdaemon/applet startup with en_US locale.
As far as I was able to test this bug, the locale change is required for ubuntuone- client- applet (OAuth module), not syncdaemon.
Syncdaemon is able to sync files with tr_TR locale.
Open gnome-session- properties, select "Ubuntu One" entry, Edit it and prefix the available command with env LC_ALL=en_US.UTF-8, so that Command (Komut) is client- applet
env LC_ALL=en_US.UTF-8 ubuntuone-
The client will be started with English/USA locale on next login. This is still a workaround but at least it will not require manual syncdaemon/applet startup with en_US locale.