keyboard shortcut switches to wrong layout

Ubuntu Saucy Salamander (development branch), Release: 13.10
package: indicator-keyboard 0.0.0+13.10.20131004-0ubuntu1

Ubuntu 13.10 is upgraded from 13.04 (which is upgraded from 12.10...)

I have installed (only) two keyboard layouts: serbian(latin) + serbian(cyrillic).
Switching between those two works correctly if using mouse to click on indicator.
Keyboard shortcut is also set ("Switch to next source using:"), i.e. Alt+Shift
When using keyboad shotcuts to change layouts it actually switches not between serbian(latin) and serbian(cyrillic) but between current layout and english QWERTY (apparently).
That is, if serbian(latin) is selected, then ALT+SHIFT, layout switches to english and back to serbian(latin), not serbian(cyrillic)
If serbian(cyrillic) is selected, then ALT+Shift, layout switches to english and back to cyrillic, not to other installed layout, serbian (latin)

Switching between keyboard layouts using ALT+SHIFT works on text consoles, content of /etc/default/keyboard is
XKBMODEL="pc105"
XKBLAYOUT="rs,rs"
XKBVARIANT="latin,"
XKBOPTIONS="grp:alt_shift_toggle,terminate:ctrl_alt_bksp"