Alt-Shift keyboard group switching

["paulie.x" <jcd seznam cz>]

Hi.
On (all) Windows default key combination to switching keyboard group is 
Alt-Shift. It's very convenient for fingers. So I activated it in Gnome. 
But on Windows the switching take place only when you press and release 
this combination. When I use for example Eclipse I use Alt-Shift-J for 
running Java program and keyboard group remains same (additional problem 
is when I must press for example M-? I must press Alt-Shift-J instead of 
Alt-Shift in gnome terminal even in pure text console. I don't know 
why). But in Gnome just pressing this combination switches group. I 
searched for any reasonable option on  "Keyboard Layout Options" in 
"Preferences->Keyboard Preferences" but I didn't found anything.
Thx