I am using xubuntu 12.04 beta2 x86_64.

Plugin is configured to ctrl-shift layout switching and behaves OK in my notebook between reboots etc.
When I attach extra USB keyboard, plugin reverts to default alt-shift switching on USB keyboard and shows alt-shift it its 'properties' window, while at the same time sensing ctrl-shift on default notebook keyboard. After manually changing to ctrl-shift in properties window, everything works OK with ctrl-shift both on USB and default keyboards, until USB keyboard detached and then attached anew, when plugin forgets its setup and starts sensing alt-shift for USB keyboard once again.

Wise behavior would be using single default setup (ctrl-shift for my case) for all attached keyboards.