Index: wp-admin/includes/ajax-actions.php
===================================================================
--- wp-admin/includes/ajax-actions.php	(revision 23507)
+++ wp-admin/includes/ajax-actions.php	(working copy)
@@ -2140,7 +2140,7 @@
 	$compareto = isset( $_GET['compareto'] ) ? absint( $_GET['compareto'] ) : 0;
 	$showautosaves = isset( $_GET['showautosaves'] ) ? $_GET['showautosaves'] : '';
 	$show_split_view = isset( $_GET['show_split_view'] ) ? $_GET['show_split_view'] : '';
-	$postid = isset( $_GET['postid'] ) ? absint( $_GET['postid'] ) : '';
+	$postid = isset( $_GET['post_id'] ) ? absint( $_GET['post_id'] ) : '';
 
 	$comparetwomode = ( '' == $postid ) ? false : true;
 	//
@@ -2149,7 +2149,6 @@
 	//so only the possible diffs need be generated
 	//
 	$alltherevisions = array();
-
 	if ( '' == $postid )
 		$postid = $compareto;
 
@@ -2159,6 +2158,7 @@
 	if ( ! $revisions = wp_get_post_revisions( $postid ) )
 		return;
 
+
 	//if we are comparing two revisions, the first 'revision' represented by the leftmost
 	//slider position is the current revision, prepend a comparison to this revision
 	if ( $comparetwomode )
Index: wp-admin/js/revisions.js
===================================================================
--- wp-admin/js/revisions.js	(revision 23507)
+++ wp-admin/js/revisions.js	(working copy)
@@ -112,7 +112,7 @@
 					self._right_handle_revisions.url =
 						ajaxurl +
 						'?action=revisions-data&compareto=' + wpRevisionsSettings.post_id +
-						'&wpRevisionsSettings.post_id=' + wpRevisionsSettings.post_id +
+						'&post_id=' + wpRevisionsSettings.post_id +
 						'&showautosaves=' + self._autosaves +
 						'&showsplitview=' +  self._showsplitview +
 						'&nonce=' + wpRevisionsSettings.nonce;
@@ -120,7 +120,7 @@
 					self._right_handle_revisions.url =
 						ajaxurl +
 						'?action=revisions-data&compareto=' + self._revisions.at( self._left_diff - 1 ).get( 'ID' ) +
-						'&wpRevisionsSettings.post_id=' + wpRevisionsSettings.post_id +
+						'&post_id=' + wpRevisionsSettings.post_id +
 						'&showautosaves=' + self._autosaves +
 						'&showsplitview=' +  self._showsplitview +
 						'&nonce=' + wpRevisionsSettings.nonce;
@@ -129,7 +129,7 @@
 				self._left_handle_revisions.url =
 					ajaxurl +
 					'?action=revisions-data&compareto=' + self._revisions.at( self._right_diff - 1 ).get( 'ID' ) +
-					'&wpRevisionsSettings.post_id=' + wpRevisionsSettings.post_id +
+					'&post_id=' + wpRevisionsSettings.post_id +
 					'&showautosaves=' + self._autosaves +
 					'&showsplitview=' +  self._showsplitview +
 					'&nonce=' + wpRevisionsSettings.nonce;