Index: nodeblock.module
--- nodeblock.module Base (BASE)
+++ nodeblock.module Locally Modified (Based On LOCAL)
@@ -181,18 +181,25 @@
  * hook_node_delete
  */
 function nodeblock_node_delete($node) {
+  $rehash = FALSE;
+  
   if(variable_get('nodeblock_block_' . $node->nid, false)) {
     variable_del('nodeblock_block_' . $node->nid);
+    $rehash = TRUE;
   }
 
   if (isset($node->nodeblock['translation_fallback'])) {
     $tnid = !empty($node->tnid) ? $node->tnid : $node->nid;
     if(variable_get('nodeblock_translation_fallback_' . $tnid, false)) {
       variable_del('nodeblock_translation_fallback_' . $tnid);
+      $rehash = TRUE;
     }  
   }
+  
+  if ($rehash) {
   _block_rehash();
 }
+}
\ No newline at end of file
 /**
  * hook_node_update
  */