Index: units/helpers/themes_helper.php
===================================================================
--- units/helpers/themes_helper.php	(revision 13168)
+++ units/helpers/themes_helper.php	(working copy)
@@ -357,6 +357,8 @@
 					$theme_id = $this->refreshTheme($filename);
 					if ($theme_id) {
 						$themes_found[] = $theme_id;
+						// increment serial of updated themes
+						$this->Application->incrementCacheSerial('theme', $theme_id);
 					}
 				}
 			}
@@ -381,6 +383,11 @@
 			$theme_ids = $this->Conn->GetCol($sql);
 			$this->deleteThemes($theme_ids);
 
+			foreach ($theme_ids as $theme_id) {
+				// increment serial of deleted themes
+				$this->Application->incrementCacheSerial('theme', $theme_id);
+			}
+
 			$this->Application->incrementCacheSerial('theme');
 			$this->Application->incrementCacheSerial('theme-file');
 		}