GTK+ accessibility

[Miroslav Rajcic <miroslav rajcic inet hr>]

Hi everyone,

recently I've received the mail from a blind user of my program 
complaining about accessibility issues.
Program is GTK+ 2.x based, he tried Windows edition.

One of the things he mentioned is that pressing Alt key in the main 
window should cause the first item in the menu bar to become focused.

I've checked other programs and it seems that:
1. Windows native programs (see Notepad for example) obey this behavior, 
pressing Alt does select menu bar item
2. created basic GTK program with menu bar, this behavior is not obeyed 
(see test source code below)
    I've played with different GTK settings like "gtk-auto-mnemonics" 
and "gtk-enable-mnemonics", but no help.

My question:
- am I missing some setting here ?
- is this unsupported?

Thanks for any tip, I'd like to improve the program accessibility for my 
users.

Regards,
  Miroslav