WP-Admin Issues

Recently, actually just as in today, I started experiencing something weird.

I can login just fine to /wp-admin/, but when I try to navigate anywhere, it asks me to download that file. Also, when I try to come back to /wp-admin/ directly, it asks me to download the file. My main blog works fine.

Is this a httpd.conf issue or a .htaccess issue or what could it be?

Thank you
Jonathan
bleakgeek.com