When adding and setting the Neo keyboard layout to be the default via the "Keyboard Layout Handler" widget in the taskbar (for instance: "German(neo), German, English"), then the left Mod3 unfortunately keeps being Caps_Lock (even the caps-lock LED lights up when hitting Left-Mod3) and the right Mod3 stays "#".
Funnily if I change the order of preference in the Settings window to for instance "German, German(neo), English" and then switching to "German(neo)" by clicking on the taskbar icon then Mod3 works perfectly fine.
Device: Odroid U3 (ARM)
Keyboard: Motorola Lapdock
OS: Ubuntu 14.04