Keyboard layouts: can't switch after upgrade to 11.2 m2

English Install/Boot/Login
#1

I have just upgraded from 11.1 to 11.2 milestone 2 and can’t switch keyboard layouts anymore. I have a Microsoft Multimedia v. 1.0 keyboard, and here is what I have in xorg.conf:

Section "InputDevice"
  Driver       "kbd"
  Identifier   "Keyboard[0]"
  Option       "Protocol" "Standard"
  Option       "XkbLayout" "us,ru,by,epo"
  Option       "XkbVariant" ",winkeys,winkeys,"
  Option       "XkbOptions" "grp:alt_shift_toggle,grp_led:scroll,lv3:win_switch"
  Option       "XkbModel" "microsoftmult"
  Option       "XkbRules" "xfree86"
EndSection

The above configuration worked fine with 10.2/10.3/11.1, so why is it wrong for 11.2 m2?

A note: if I launch KKbswitch, it shows me that only the US layout is available in the system.