When i have written the previous entry on aligning menu items in Swing applications, i was blissfully ignorant and thought that the life was good. Thankfully, one of the users of Substance has opened this defect with the following summary - "Menu texts are invisible in RTL orientation".
Why, say you. What's that RTL has to do with my application? Turns out that there are four locales that define the right-to-left orientation (who should know better than me...), Arabic (ar), Hebrew (iw), Persian (fa) and Urdu (ur). Under these locales, the users expect their applications to be layed-out correspondingly. Swing core look-and-feels provide quite a good support for this:
These two screenshots of Metal in Tiger and Metal in Mustang (you can see that Mustang properly aligns the texts, but fails quite miserably at aligning the accelerators):
The same problem with the accelerator alignment on RTL menus under Mustang is with the Windows LAF:
And what happens with the third-party LAFs you ask? Well, it depends. Here's a short chart of nine third-party open-source and commercial LAFs sorted by the degree of current RTL support in the menus (both under Tiger and Mustang):

- The first place - JGoodies' Looks. The only problem is with the accelerator alignment (both on Tiger and on Mustang). The first place doesn't come easy though - JGoodies provides its own layout and painting mechanism and as such, it uses the SwingUtilities2 class which is unsupported. Hence, this ungodly creature in the codebase of 2.0beta:

          private static final String SWING_UTILITIES2_NAME =
              LookUtils.IS_JAVA_6_OR_LATER
                   ? "sun.swing.SwingUtilities2"
                   : "com.sun.java.swing.SwingUtilities2";

  The screenshots for Tiger and Mustang (note the accelerator alignment problem which is better in Mustang but still slightly off - this has been fixed for Beta2 coming in the next few days):
- The second place - Substance (would have been sixth and the last place yesterday). Both under Tiger and Mustang properly aligned texts, but the accelerators are off. The main hindrance to getting this to work (not only in Substance but also in all other Metal-extending LAFs below) is that the UI delegates for menu items do not provide hooks for painting the accelerators. The only available way is JGoodies way - do it yourself (and be bound to use SwingUtilities2). The screenshots for Tiger and Mustang (note the accelerator alignment problem present in both):
- Third place - Pagosoft, Squareness and Napkin. In addition to the accelerator alignment as above, the texts aren't aligned under Tiger (core fix in Mustang). The screenshots of Pagosoft for Tiger and Mustang (note the text alignment under Tiger):
  The screenshots of Squareness for Tiger and Mustang (note the text alignment under Tiger):
  The screenshots of Napkin for Tiger and Mustang (including Tiger workaround for this bug fixed in Mustang):
- Fourth place - Synthetica (commercial) and Trendy (commercial). In addition to the accelerator alignment and text alignment under Tiger, the arrow points to the right and not to the left. The screenshots of Synthetica for Tiger and Mustang (note the arrow direction):
  The screenshots of Trendy for Tiger and Mustang (note the arrow direction):
- Fifth place - Liquid and Tiny. The RTL menus are completely messed up both under Tiger and Mustang. Screenshots of Liquid and Tiny under Mustang:
- Sixth place - Office (and Substance yesterday). No support at all for RTL menus - the menus are layed out left-to-right. Screenshot under Mustang:

The above support for RTL menus in Substance is available in the release candidate of version 2.2. In addition, the version 2.3 will provide full support for RTL features (including additional UI elements that Substance adds). Great thanks to the reporter that made me finally think of this and let's hope that the accelerator alignment issue will be addressed in the final release of Mustang.