Index: bbp-includes/bbp-reply-functions.php
===================================================================
--- bbp-includes/bbp-reply-functions.php	(revision 2932)
+++ bbp-includes/bbp-reply-functions.php	(working copy)
@@ -428,6 +428,10 @@
 	// Verifiy the reply ID
 	if ( $reply_id = bbp_get_reply_id ( $reply_id ) ) {
 
+		// Make sure the reply isn't marked as spam or deleted by a plugin.
+		if ( get_post_field( 'post_status', $topic_id ) != 'publish' )
+			return;
+
 		// Get the topic ID if none was passed
 		if ( empty( $topic_id ) )
 			$topic_id = bbp_get_reply_topic_id ( $reply_id );
Index: bbp-includes/bbp-topic-functions.php
===================================================================
--- bbp-includes/bbp-topic-functions.php	(revision 2932)
+++ bbp-includes/bbp-topic-functions.php	(working copy)
@@ -447,6 +447,7 @@
  * @param int $topic_id
  *
  * @uses bbp_get_topic_id()
+ * @uses get_post_field()
  * @uses bbp_get_topic_forum_id()
  * @uses get_post_ancestors()
  * @uses bbp_is_forum()
@@ -457,6 +458,10 @@
 	// Validate topic_id
 	if ( $topic_id = bbp_get_topic_id( $topic_id ) ) {
 
+		// Make sure the topic isn't marked as spam or deleted by a plugin.
+		if ( get_post_field( 'post_status', $topic_id ) != 'publish' )
+			return;
+
 		// Get the forum ID if none was passed
 		if ( empty( $forum_id )  )
 			$forum_id = bbp_get_topic_forum_id( $topic_id );