Thanks for the suggestions!

With your guidance I believe I have isolated the problem, more or less. When I try to open the Java prefs for J2SE 5, the window is blank--just like the LimeWire setup window! When I then go to open Java 4.2 settings, the window is blank again. When I open Java 1.3.1 I get the dialog box.

I was able to install LimeWire just fine on a second account I set up on my machine.

I downloaded an J2SE 5 installer from apple.com but it wouldn't install. I couldn't get past the step that identifies volumes available for installing.

So I'm guessing that the problem lies somewhere in my Java installation, going back to Java 4. Do you have any thoughts about this?

One last thought: I use Firefox browser, the most recent version. For more than a year, I've noticed that buttons on all web pages (such as the "Post Quick Reply" and "Go Advanced" just below this window) do not show; only the words themselves. It's been a minor annoyance, and I've posted on the Firefox forum for help on that, but have received no replies. Now I suspect that this may be a symptom of the same issue I'm having with LimeWire.