Well, after fighting with lightbox2 some more, I decided to try shadowbox, and it worked as advertised without any changes, so I switched to that.
Once complaint about shadowbox - it appears as if some sort of obfuscation has been applied because all of the variables and method names are either one or two characters long. This makes it pretty much impossible to figure out what the guy did or modify the code to suit your own needs. Of course, there aren't any comments either.
Anyway, if anyone else wants to explore the wonderful world of lightbox technology, here's a link to a page that lists a few dozen different approaches, supporting pretty much any javascript framework you might happen to name:
Lightbox clones[
^]
The only thing you really have to do is consult the chart, and pick the lightbox code that best fits your needs. FWIW, Shadowbox allows you to pick the framework and the feature set, thus allowing you to tailor your download and how much overhead and dependency crap you really want to deal with.