In testing some other changes, I discovered that the relative paths in the menu bar for the faculty members' pages was incorrect. Problem very similar to the one I found earlier in the graduate colloquium page. Solved by using the same session variable assignment.
$_SESSION['level'] = "L2";
There is a variable called $level obviously intended to do this job, but the value in that var is not being maintained from page to page (of course). I'm sure that was working when Clifton wrote it, so either some code that hooks that $level var to a SESSION array has been accidentally deleted, or a change in the version of PHP running (or the config on it) has caused what used to be working to now fail.
Had to add that line of code to about 40 files in about a dozen directories.