Xubuntu 15 + lightdm + onboard login problem

[sergey1369]

Hello.

I'm on Xubuntu 15.04. I've got a tablet and everything works fine except login screen.

The onboard appears onscreen, but I can't enter characters in password field.
They doesn't appear - "no dots". Looks like characters are routed to root window
instead of login prompt.

If I login to xfce with physical keybord everything works fine.
The problem persists only on login screen.

Please advice, what should I do to make onboard work correctly?

Thanks in advance, Sergey.