As I said in my firs post, I'm not willing to run a whole desktop like Gnome or Kde. Actually I tried, but this machine is far too old for it. And I don't really want to switch from a Windows gui to another gui.
Also, the problem is not in switching the keyboard layout, it does switch, but once switched I cannot input the extra characters. That is, under russian keyboard if I press the keys for "." or "," and the likes which are commom, I get them printed in terminal, but if I press the letters nothing comes out. The same for accented characters, if I press "รจ" I get nothing, or funny garbage. But as you see, here in firefox (which eats up over 100 M of my 190 M ram...) it works, but in terminal-based applications it does not.
This is the problem I'm stuck with.
In case it should be of any help, this is what xev reports when I press "a" under russian keyboard layout:
KeyPress event, serial 25, synthetic NO, window 0x1400001,
root 0x46, subw 0x0, time 1804070102, (60,2), root
576,318),
state 0x4000, keycode 38 (keysym 0x6c6, Cyrillic_ef), same_screen YES,
XLookupString gives 0 bytes:
XmbLookupString gives 0 bytes:
XFilterEvent returns: False
KeyRelease event, serial 25, synthetic NO, window 0x1400001,
root 0x46, subw 0x0, time 1804070229, (60,2), root
576,318),
state 0x4000, keycode 38 (keysym 0x6c6, Cyrillic_ef), same_screen YES,
XLookupString gives 0 bytes:
XFilterEvent returns: False
Thank you anyway for your help.