memeces: thx for testing.

Please try the following:
Check the file /home/user/.dropn900/settings.ini, it should be something like this:

[download]
default-folder = /home/user/MyDocs/DropN900/
no-dialog = true

[automated-sync]
only-sync-on-wlan = false
update-interval = 10
sync-path = /
enabled = false

[authentication]
store-auth = true

Next: Start DropN900 and open the settings window. Set a local path, e. g. /home/user/MyDocs/DropN900. Under synchronizing press the button with no text, which we already talked about, and select the root folder /. Store the settings and check the settings.ini file again.

If your settings are correct and you still cannot sync plz report back and i'll make a dropn900 version with extended logging.