In several gtk2 applications I have tried (galeon-1.3.7, gaim-0.68 and 
even the filesel example from gtk2) I have serious problem with 
simple key press.

Any time I press a key, the result is as if I have pressed the Alt key also.

I have compiled the filesel example with debug gtk2 and the relevant part of 
debug info is:

   Gdk-Message: key press  :        window: 41943043         key: c 99
   Gdk-Message:            length:    1 string: "c"
   Gtk-Message: Looking up keycode = 54, modifiers = 0x0000,
    keyval = 99, group = 0, level = 0, consumed_modifiers = 0x608b
   Gtk-Message:   found exact match, keyval = 99, modifiers = 0x0008
   Gtk-Message:   found exact match, keyval = 99, modifiers = 0x0008
   Gdk-Message: key release:         window: 41943043        key: c 99
   Gdk-Message:            length:    1 string: "c"

It seems to me, that the problem is between the 3rd and 4th message, where
the modifiers changes from 0x0000 to 0x0008.

I do not have a clue about how to correct this situation.