switch keyboard layout

[George <siberianowl yahoo com>]

I am using Gnome 2.32 (Ubuntu 10.10).
By using the supplied keyboard configuration utility I successfully set 
up two language layouts and they work perfectly.
Since I also often work on Windows and default shortcut to switch 
layouts in it is Alt+Shift and after many years I am very used to this, 
I tried to setup the same shortcut in Gnome.
But with a Gnome I have a problem: once I press Alt+Shift - layouts 
switch immediately and I am unable to do Alt+Shift+<Something> shortcuts.

So my main question is:
Is it possible to teach Gnome's keyboard layout switcher to do the 
actual switch of layouts only if I press and release the Alt+Shift 
combination without touching any other keys?

If there is a more suitable news-group for this question, please tell me.