Index: bbp-includes/bbp-user-functions.php
===================================================================
--- bbp-includes/bbp-user-functions.php	(revision 3854)
+++ bbp-includes/bbp-user-functions.php	(working copy)
@@ -232,7 +232,7 @@
 	global $wpdb;
 
 	// Get the users who have favorited the topic
-	$users = $wpdb->get_col( "SELECT user_id FROM {$wpdb->usermeta} WHERE meta_key = '_bbp_favorites' and FIND_IN_SET('{$topic_id}', meta_value) > 0" );
+	$users = $wpdb->get_col( "SELECT user_id FROM {$wpdb->usermeta} WHERE meta_key = '_bbp_" . $wpdb->prefix . "favorites' and FIND_IN_SET('{$topic_id}', meta_value) > 0" );
 	$users = apply_filters( 'bbp_get_topic_favoriters', $users, $topic_id );
 
 	if ( !empty( $users ) )
@@ -288,7 +288,9 @@
 		if ( empty( $user_id ) )
 			return false;
 
-		$favorites = (string) get_user_meta( $user_id, '_bbp_favorites', true );
+		global $wpdb;
+
+		$favorites = (string) get_user_meta( $user_id, '_bbp_' . $wpdb->prefix . 'favorites', true );
 		$favorites = (array) explode( ',', $favorites );
 		$favorites = array_filter( $favorites );
 
@@ -369,7 +371,10 @@
 		$favorites[] = $topic_id;
 		$favorites   = array_filter( $favorites );
 		$favorites   = (string) implode( ',', $favorites );
-		update_user_meta( $user_id, '_bbp_favorites', $favorites );
+		
+		global $wpdb;
+		
+		update_user_meta( $user_id, '_bbp_' . $wpdb->prefix . 'favorites', $favorites );
 	}
 
 	do_action( 'bbp_add_user_favorite', $user_id, $topic_id );
@@ -404,11 +409,13 @@
 		array_splice( $favorites, $pos, 1 );
 		$favorites = array_filter( $favorites );
 
+		global $wpdb;
+
 		if ( !empty( $favorites ) ) {
 			$favorites = implode( ',', $favorites );
-			update_user_meta( $user_id, '_bbp_favorites', $favorites );
+			update_user_meta( $user_id, '_bbp_' . $wpdb->prefix . 'favorites', $favorites );
 		} else {
-			delete_user_meta( $user_id, '_bbp_favorites' );
+			delete_user_meta( $user_id, '_bbp_' . $wpdb->prefix . 'favorites' );
 		}
 	}
 
@@ -535,7 +542,7 @@
 
 	$users = wp_cache_get( 'bbp_get_topic_subscribers_' . $topic_id, 'bbpress' );
 	if ( empty( $users ) ) {
-		$users = $wpdb->get_col( "SELECT user_id FROM {$wpdb->usermeta} WHERE meta_key = '_bbp_subscriptions' and FIND_IN_SET('{$topic_id}', meta_value) > 0" );
+		$users = $wpdb->get_col( "SELECT user_id FROM {$wpdb->usermeta} WHERE meta_key = '_bbp_" . $wpdb->prefix . "subscriptions' and FIND_IN_SET('{$topic_id}', meta_value) > 0" );
 		wp_cache_set( 'bbp_get_topic_subscribers_' . $topic_id, $users, 'bbpress' );
 	}
 
@@ -593,7 +600,9 @@
 	if ( empty( $user_id ) )
 		return false;
 
-	$subscriptions = (string) get_user_meta( $user_id, '_bbp_subscriptions', true );
+	global $wpdb;
+
+	$subscriptions = (string) get_user_meta( $user_id, '_bbp_' . $wpdb->prefix . 'subscriptions', true );
 	$subscriptions = (array) explode( ',', $subscriptions );
 	$subscriptions = array_filter( $subscriptions );
 
@@ -677,7 +686,10 @@
 		$subscriptions[] = $topic_id;
 		$subscriptions   = array_filter( $subscriptions );
 		$subscriptions   = (string) implode( ',', $subscriptions );
-		update_user_meta( $user_id, '_bbp_subscriptions', $subscriptions );
+		
+		global $wpdb;
+		
+		update_user_meta( $user_id, '_bbp_' . $wpdb->prefix . 'subscriptions', $subscriptions );
 
 		wp_cache_delete( 'bbp_get_topic_subscribers_' . $topic_id, 'bbpress' );
 	}
@@ -716,11 +728,13 @@
 		array_splice( $subscriptions, $pos, 1 );
 		$subscriptions = array_filter( $subscriptions );
 
+		global $wpdb;
+
 		if ( !empty( $subscriptions ) ) {
 			$subscriptions = implode( ',', $subscriptions );
-			update_user_meta( $user_id, '_bbp_subscriptions', $subscriptions );
+			update_user_meta( $user_id, '_bbp_' . $wpdb->prefix . 'subscriptions', $subscriptions );
 		} else {
-			delete_user_meta( $user_id, '_bbp_subscriptions' );
+			delete_user_meta( $user_id, '_bbp_' . $wpdb->prefix . 'subscriptions' );
 		}
 
 		wp_cache_delete( 'bbp_get_topic_subscribers_' . $topic_id, 'bbpress' );
Index: bbp-admin/bbp-tools.php
===================================================================
--- bbp-admin/bbp-tools.php	(revision 3854)
+++ bbp-admin/bbp-tools.php	(working copy)
@@ -723,7 +723,7 @@
 	$statement = __( 'Removing trashed topics from user favorites… %s', 'bbpress' );
 	$result    = __( 'Failed!', 'bbpress' );
 
-	$users = $wpdb->get_results( "SELECT `user_id`, `meta_value` AS `favorites` FROM `$wpdb->usermeta` WHERE `meta_key` = '_bbp_favorites';" );
+	$users = $wpdb->get_results( "SELECT `user_id`, `meta_value` AS `favorites` FROM `$wpdb->usermeta` WHERE `meta_key` = '_bbp_" . $wpdb->prefix . "favorites';" );
 	if ( is_wp_error( $users ) )
 		return array( 1, sprintf( $statement, $result ) );
 
@@ -742,7 +742,7 @@
 			continue;
 
 		$favorites = join( ',', $favorites );
-		$values[] = "('$user->user_id', '_bbp_favorites', '$favorites')";
+		$values[] = "('$user->user_id', '_bbp_" . $wpdb->prefix . "favorites', '$favorites')";
 	}
 
 	if ( !count( $values ) ) {
@@ -750,7 +750,7 @@
 		return array( 0, sprintf( $statement, $result ) );
 	}
 
-	$sql_delete = "DELETE FROM `$wpdb->usermeta` WHERE `meta_key` = '_bbp_favorites';";
+	$sql_delete = "DELETE FROM `$wpdb->usermeta` WHERE `meta_key` = '_bbp_" . $wpdb->prefix . "favorites';";
 	if ( is_wp_error( $wpdb->query( $sql_delete ) ) )
 		return array( 4, sprintf( $statement, $result ) );