open_basedir error

I recently followed these steps (https://wpmututorials.com/news/new-features/multiple-buddypress-social-networks/) to use multiple distinct buddypress networks. It essentially installs buddypress on individual wordpress subnetworks that were created using WP Multi Network plugin.

This all works fine but for one problem (that seems to be purely
aesthetic but rather disruptive on the page). On the dashboard for the
wordpress subnetwork with buddypress activated, and on the actual
pages themselves, I get the following error:

Warning: file_exists() [function.file-exists]: open_basedir restriction in effect.
File(/avatars/1) is not within the allowed path(s):
(/f5/[mysite]/:/nfsn/apps/php53/lib/php/:/nfsn/apps/php5/lib/php/:/nfsn/apps/php/lib/php/)
in /f5/[mysite]/public/wp-content/plugins/buddypress/bp-core/bp-core-avatars.php on line 195

So again, this is displayed on the dashboard and on the pages
(anywhere where there is an avatar).

I got a reply from the buddypress people saying: “Your host has a PHP
setting known as “open_basedir” in effect. Ask them to turn it
off, and show them that error message.” But my host (NearlyFreeSpeech) runs PHP in safe mode. Is there any other way to deal with this?

I just want the error to go away on my page and in the dashboard. Can
you help please? Anything you can do to help would be greatly
appreciated.

The bottom of my wp-config.php file:

*/
define('WP_DEBUG', false);

define('WP_TEMP_DIR',ABSPATH.'tmp');

define( 'MULTISITE', true );
define( 'SUBDOMAIN_INSTALL', true );
$base = '/';
define( 'DOMAIN_CURRENT_SITE', '[mysite]' );
define( 'PATH_CURRENT_SITE', '/' );
define( 'SITE_ID_CURRENT_SITE', 1 );
define( 'BLOG_ID_CURRENT_SITE', 1 );

/* That's all, stop editing! Happy blogging. */

/** Absolute path to the WordPress directory. */
if ( !defined('ABSPATH') )
	define('ABSPATH', dirname(__FILE__) . '/');

/** Sets up WordPress vars and included files. */
require_once(ABSPATH . 'wp-settings.php');

if(is_admin()) {
add_filter('filesystem_method', create_function('$a', 'return "direct";' ));
define( 'FS_CHMOD_DIR', 0751 );
}

And htaccess:

# BEGIN WordPress
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# uploaded files
RewriteRule ^files/(.+) wp-includes/ms-files.php?file=$1 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?siteN/files/(.+) wp-content/blogs.dir/N/files/$2 [L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule . index.php [L]
# END WordPress

Thanks for any assistance.