Sorry for the flurry of posts . . . In the spirit of troubleshooting, I changed the permalink structure to something pretty, and updated my htaccess file accordingly (see below). Still no access to the calendar via URL/calendar path.
HTACCESS CODE:
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^calendar/([^/.]+)/([^/.]+)/?$ wp-calendar.php?year=$1&month=$2 [QSA,L] RewriteRule ^calendar/?$ wp-calendar.php [QSA,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress