In all browsers other than FF for Mac, the css for the items in the popup list of options is corrupted. The cause is that in search.css.php the code is looking for variables such as $_browser_is_ie, and I'd removed the code that defined (in config.php) and set values for (in browserdetect.inc) those variables.

When I inserted the appropriate code, then the css in the popup window worked properly, but the css in the main search window appears to be compeletely disabled. Obviously I'll have to figure out why that is happening. ML has said this is a lower priority than other issues, so I'll deal with those other issues before returning to this one.