error 500 – cannot access dashboards or wp-admin for subdomains

(WP 3.0.4, BP 1.2.7)

i recently upgraded to WP 3.0.4, and had many an issue with permalinks. i sorted that all out, but there is an issue where nobody can access their dashboard (or login) via /wp-admin. As the super admin, I also cannot login to their backend via SuperAdmin | Sites | Backend.

If they go to their “subdomain” they receive an error 500

If they go to they get the login screen, but then it redirects them to and they have no access to their dashboard.

If I go to SuperAdmin | Sites | Backend for any subdomain, i get a blank page.

Any ideas?