Index: bp-core-signup.php
===================================================================
--- bp-core-signup.php	(revision 2943)
+++ bp-core-signup.php	(working copy)
@@ -90,7 +90,7 @@
 		/* Add any errors to the action for the field in the template for display. */
 		if ( !empty( $bp->signup->errors ) ) {
 			foreach ( (array)$bp->signup->errors as $fieldname => $error_message )
-				add_action( 'bp_' . $fieldname . '_errors', create_function( '', 'echo "<div class=\"error\">' . $error_message . '</div>";' ) );
+				add_action( 'bp_' . $fieldname . '_errors', create_function( '', "echo apply_filters( 'bp_signup_errors', '" . $error_message . "' );" ) );
 		} else {
 			$bp->signup->step = 'save-details';