Please see attched image file.
Mnemonic Keys which was mistaken on the Japanese
is attached.
To reproduce: Tool -> Setup Wizard -> Step 2
The Mnemonic Keys of "Built-in Editor"

Would you check if the first character is not used
as mnemonic key?
By localization, the first character becomes
no-ascii character. As a
result, the mnemonic key doesn't work by
localization. To fix this
problem, we need to set two resource bundle
messages, one is for 
caption, another is for mnemonic.
  Example=TestString
  Example_Mnemonic=T

And we should use like this:
myButton.setText(myBundle.getString("Example"));
myButton.setMnemonic(myBundle.getString("Example_Mnemonic").charAt(0).

The following line does not work with localized
version, because the
first character is not an alphanumeric because
it's replaced to
multi-byte Japanese character.

*OS:Solaris 5.8  
*Orion Build:orion_ml_020429  fcc Build:20.4
*JDK:JDK1.4.0
*locale:ja