Index: wp-includes/query.php
===================================================================
--- wp-includes/query.php	(revision 11959)
+++ wp-includes/query.php	(working copy)
@@ -2070,17 +2070,21 @@
 				$q['orderby'] = "$wpdb->posts.post_date ".$q['order'];
 		}
 
+		$post_type_cap = $post_type;
+
 		if ( 'any' == $post_type ) {
 			$where .= " AND $wpdb->posts.post_type != 'revision'";
 		} elseif ( ! empty( $post_type ) ) {
 			$where .= " AND $wpdb->posts.post_type = '$post_type'";
 		} elseif ( $this->is_attachment ) {
 			$where .= " AND $wpdb->posts.post_type = 'attachment'";
+			$post_type_cap = 'post';
 		} elseif ($this->is_page) {
 			$where .= " AND $wpdb->posts.post_type = 'page'";
+			$post_type_cap = 'page';
 		} else {
 			$where .= " AND $wpdb->posts.post_type = 'post'";
-			$post_type = 'post';
+			$post_type_cap = 'post';
 		}
 
 		if ( isset($q['post_status']) && '' != $q['post_status'] ) {
@@ -2109,13 +2113,13 @@
 			}
 
 			if ( !empty($r_status) ) {
-				if ( !empty($q['perm'] ) && 'editable' == $q['perm'] && !current_user_can("edit_others_{$post_type}s") )
+				if ( !empty($q['perm'] ) && 'editable' == $q['perm'] && !current_user_can("edit_others_{$post_type_cap}s") )
 					$statuswheres[] = "($wpdb->posts.post_author = $user_ID " .  "AND (" . join( ' OR ', $r_status ) . "))";
 				else
 					$statuswheres[] = "(" . join( ' OR ', $r_status ) . ")";
 			}
 			if ( !empty($p_status) ) {
-				if ( !empty($q['perm'] ) && 'readable' == $q['perm'] && !current_user_can("read_private_{$post_type}s") )
+				if ( !empty($q['perm'] ) && 'readable' == $q['perm'] && !current_user_can("read_private_{$post_type_cap}s") )
 					$statuswheres[] = "($wpdb->posts.post_author = $user_ID " .  "AND (" . join( ' OR ', $p_status ) . "))";
 				else
 					$statuswheres[] = "(" . join( ' OR ', $p_status ) . ")";
@@ -2134,7 +2138,7 @@
 				$where .= " OR $wpdb->posts.post_status = 'future' OR $wpdb->posts.post_status = 'draft' OR $wpdb->posts.post_status = 'pending'";
 
 			if ( is_user_logged_in() ) {
-				$where .= current_user_can( "read_private_{$post_type}s" ) ? " OR $wpdb->posts.post_status = 'private'" : " OR $wpdb->posts.post_author = $user_ID AND $wpdb->posts.post_status = 'private'";
+				$where .= current_user_can( "read_private_{$post_type_cap}s" ) ? " OR $wpdb->posts.post_status = 'private'" : " OR $wpdb->posts.post_author = $user_ID AND $wpdb->posts.post_status = 'private'";
 			}
 
 			$where .= ')';
@@ -2310,7 +2314,7 @@
 				}
 			}
 
-			if ( $this->is_preview && current_user_can( "edit_{$post_type}", $this->posts[0]->ID ) )
+			if ( $this->is_preview && current_user_can( "edit_{$post_type_cap}", $this->posts[0]->ID ) )
 				$this->posts[0] = apply_filters('the_preview', $this->posts[0]);
 		}