diff --git a/comicpress_manager_admin.php b/comicpress_manager_admin.php
index 8cfe41a..a0ac674 100644
--- a/comicpress_manager_admin.php
+++ b/comicpress_manager_admin.php
@@ -151,52 +151,54 @@ function cpm_handle_pre_post_update($post_id) {
 
   if (!$cpm_config->is_cpm_managing_posts) {
     if (cpm_option("cpm-edit-post-integrate") == 1) {
-      $post = get_post($post_id);
-      if (!in_array($post->post_type, array("attachment", "revision", "page"))) {
-        $ok = false;
-        extract(cpm_get_all_comic_categories());
-        $post_categories = wp_get_post_categories($post_id);
-        foreach ($category_tree as $node) {
-          $parts = explode("/", $node);
-          if (in_array(end($parts), $post_categories)) {
-            $ok = true; break;
-          }
-        }
-
-        if ($ok) {
-          $original_timestamp = false;
-          foreach (array("post_date", "post_date_gmt") as $param) {
-            $result = strtotime(date("Y-m-d", strtotime($post->{$param})));
-            if ($result !== false) {
-              $original_timestamp = $result; break;
+      if ($post_id > 0) {
+        $post = get_post($post_id);
+        if (!in_array($post->post_type, array("attachment", "revision", "page"))) {
+          $ok = false;
+          extract(cpm_get_all_comic_categories());
+          $post_categories = wp_get_post_categories($post_id);
+          foreach ($category_tree as $node) {
+            $parts = explode("/", $node);
+            if (in_array(end($parts), $post_categories)) {
+              $ok = true; break;
             }
           }
 
-          $new_timestamp = strtotime(implode("-", array($_POST['aa'], $_POST['mm'], $_POST['jj'])));
-
-          if (!empty($original_timestamp) && !empty($new_timestamp)) {
-            $original_date = date(CPM_DATE_FORMAT, $original_timestamp);
-            $new_date = date(CPM_DATE_FORMAT, $new_timestamp);
-
-            if ($original_date !== $new_date) {
-              if (empty($cpm_config->comic_files)) {
-                cpm_read_information_and_check_config();
+          if ($ok) {
+            $original_timestamp = false;
+            foreach (array("post_date", "post_date_gmt") as $param) {
+              $result = strtotime(date("Y-m-d", strtotime($post->{$param})));
+              if ($result !== false) {
+                $original_timestamp = $result; break;
               }
+            }
 
-              foreach ($cpm_config->comic_files as $file) {
-                $filename = pathinfo($file, PATHINFO_BASENAME);
-                if (($result = cpm_breakdown_comic_filename($filename)) !== false) {
-                  if ($result['date'] == $original_date) {
-                    foreach (cpm_find_thumbnails_by_filename($file) as $thumb_file) {
-                      @rename($thumb_file, str_replace("/${original_date}", "/${new_date}", $thumb_file));
+            $new_timestamp = strtotime(implode("-", array($_POST['aa'], $_POST['mm'], $_POST['jj'])));
+
+            if (!empty($original_timestamp) && !empty($new_timestamp)) {
+              $original_date = date(CPM_DATE_FORMAT, $original_timestamp);
+              $new_date = date(CPM_DATE_FORMAT, $new_timestamp);
+
+              if ($original_date !== $new_date) {
+                if (empty($cpm_config->comic_files)) {
+                  cpm_read_information_and_check_config();
+                }
+
+                foreach ($cpm_config->comic_files as $file) {
+                  $filename = pathinfo($file, PATHINFO_BASENAME);
+                  if (($result = cpm_breakdown_comic_filename($filename)) !== false) {
+                    if ($result['date'] == $original_date) {
+                      foreach (cpm_find_thumbnails_by_filename($file) as $thumb_file) {
+                        @rename($thumb_file, str_replace("/${original_date}", "/${new_date}", $thumb_file));
+                      }
+
+                      @rename($file, str_replace("/${original_date}", "/${new_date}", $file));
                     }
-
-                    @rename($file, str_replace("/${original_date}", "/${new_date}", $file));
                   }
                 }
-              }
 
-              $cpm_config->comic_files = null;
+                $cpm_config->comic_files = null;
+              }
             }
           }
         }
diff --git a/comicpress_manager_library.php b/comicpress_manager_library.php
index 6a6825e..c6d319a 100644
--- a/comicpress_manager_library.php
+++ b/comicpress_manager_library.php
@@ -376,8 +376,14 @@ function cpm_read_information_and_check_config() {
         $cpm_config->thumbs_folder_writable[$thumb_type] = true;
       }
     }
-    $cpm_config->comic_category_info = get_object_vars(get_category($cpm_config->properties['comiccat']));
-    $cpm_config->blog_category_info = get_object_vars(get_category($cpm_config->properties['blogcat']));
+
+    foreach (array('comic', 'blog') as $type) {
+      $result = (object)get_category($cpm_config->properties["${type}cat"]);
+      if (!is_wp_error($result)) {
+        $cpm_config->{"${type}_category_info"} = get_object_vars($result);
+      }
+    }
+
     $cpm_config->comic_files = cpm_read_comics_folder();
   } else {
     // quick check to see if the theme is ComicPress.