@Pete – for locale independent strings try the "$ID/englishname" method.
For example, in my German InDesign CS5.5 the visibility of the "Articles" panel can be set with:
app.panels.itemByName("$ID/Articles").visible = true;
the German locale for "Articles" is "Artikel", so it's the same for the German InDesign to say:
app.panels.itemByName("Artikel").visible = true;