There's a font issue with Lion and Snow Leopard systems that can be at issue here. As a test, try changing the font of one of these fields while you have it open on the Mac 10.6 0r 10.7 system. See if the font change makes the text appear. If you do, you likely have an extra copy of that font's suitcase that needs to be removed. You can search this forum for a more detailed description if you use "Snow Leopard Font" as your search text. (I'm not a mac user, so I'm hazy on the exact details.)
PhilModjunk: That was it. There were duplicate copies of Arial in the suitcase (!?); removing the extras did the trick. Not likely to have discovered this one on my own. Thanks!