beeeerock on "[Plugin: Better WP Security] 403 Error Running wp-cron from Crontab"

I have two sites running Better WP Security, one a typical WordPress install, the second incorporating BuddyPress and bbPress.

In an effort to improve performance I disabled the triggering of wp-cron.php with page loads in wp-config.php and instead created entries in crontab like this:

0,10,20,30,40,50 * * * * /usr/bin/lynx http://www.mywebsite.net/wp-cron.php -dump > /dev/null

I did this for both sites. On the simple site it seems to work, but I see a 403 error on the BuddyPress site. I suspect it has something to do with the settings in Better WP Security but I can't work out what I've done differently. I'm guessing it relates to .htaccess but beyond that I'm at a loss. Any suggestions as to where I should be looking?

http://wordpress.org/extend/plugins/better-wp-security/