Index: bp-themes/bp-default/registration/register.php
===================================================================
--- bp-themes/bp-default/registration/register.php	(revision 4385)
+++ bp-themes/bp-default/registration/register.php	(working copy)
@@ -181,7 +181,7 @@
 							<?php do_action( 'bp_signup_blog_url_errors' ) ?>
 
 							<?php if ( is_subdomain_install() ) : ?>
-								http:// <input type="text" name="signup_blog_url" id="signup_blog_url" value="<?php bp_signup_blog_url_value() ?>" /> .<?php echo str_replace( 'http://', '', site_url() ) ?>
+								http:// <input type="text" name="signup_blog_url" id="signup_blog_url" value="<?php bp_signup_blog_url_value() ?>" /> .<?php echo preg_replace( '|^https?://(?:www\.)|', '', site_url() ) ?>
 							<?php else : ?>
 								<?php echo site_url() ?>/ <input type="text" name="signup_blog_url" id="signup_blog_url" value="<?php bp_signup_blog_url_value() ?>" />
 							<?php endif; ?>
Index: bp-blogs/bp-blogs-template.php
===================================================================
--- bp-blogs/bp-blogs-template.php	(revision 4385)
+++ bp-blogs/bp-blogs-template.php	(working copy)
@@ -434,7 +434,7 @@
 	if ( !is_subdomain_install() )
 		echo '<span class="prefix_address">' . $current_site->domain . $current_site->path . '</span> <input name="blogname" type="text" id="blogname" value="'.$blogname.'" maxlength="50" /><br />';
 	else
-		echo '<input name="blogname" type="text" id="blogname" value="'.$blogname.'" maxlength="50" /> <span class="suffix_address">.' . $current_site->domain . $current_site->path . '</span><br />';
+		echo '<input name="blogname" type="text" id="blogname" value="'.$blogname.'" maxlength="50" /> <span class="suffix_address">.' . preg_replace( '|^www\.|', '', $current_site->domain ) . $current_site->path . '</span><br />';
 
 	if ( !is_user_logged_in() ) {
 		print '(<strong>' . __( 'Your address will be ' , 'buddypress');