multi-site with WordPress stopped working

Someone there gave me the necessary .htaccess code about a year and a half ago so that I could have my Omeka site (http://music-scholars.net or http://ourmus.net ) at the public_html root of my hosting installation, while also having an addon, Wordpress site (http://durrellbowman.com) in a folder. Things went flaky yesterday. First, the Omeka site didn't load (it found some cryptic version of my personal site, perhaps without CSS), but the WordPress site did. Then, the Omeka site started working again, but the WordPress site started giving me Internal Server and 500 Errors. I've tried restoring everything to a week ago and also replacing some of the .htaccess files with ones that worked earlier. The WordPress site still won't work, giving me just a white screen of nothing (500 Internal Server Error showing at the tab). I have also restored the databases to match the site restores.

I guess there was some plugin problem. Never mind!