Index: branches/5.2.x/core/kernel/nparser/ntags.php
===================================================================
--- branches/5.2.x/core/kernel/nparser/ntags.php
+++ branches/5.2.x/core/kernel/nparser/ntags.php
@@ -323,7 +323,7 @@
 		}
 		$this->Single = false;
 		$this->OriginalTag = $tag;
-		$tag['NP']['name'] = $tag['NP']['design'] . '_' . abs(crc32($tag['file'])) . '_' . $tag['line']; //'__lambda';
+		$tag['NP']['name'] = $this->createSafeFunctionName($tag);
 
 		return parent::Open($tag);
 	}
@@ -341,11 +341,26 @@
 			return $this->Parser->Buffers[$this->Parser->Level];
 		}
 		$o = parent::Close($tag);
-		$this->OriginalTag['NP']['name'] = $this->OriginalTag['NP']['design'] . '_' . abs(crc32($this->OriginalTag['file'])) . '_' . $this->OriginalTag['line']; //'__lambda';
+		$this->OriginalTag['NP']['name'] = $this->createSafeFunctionName($this->OriginalTag);
 
 		$this->RenderDesignCode($o, $this->OriginalTag['NP']);
 		return $o;
 	}
+
+	/**
+	 * Creates safe function name based on design used in a given tag.
+	 *
+	 * @param array $tag Tag.
+	 *
+	 * @return string
+	 */
+	protected function createSafeFunctionName(array $tag)
+	{
+		$safe_design = preg_replace('/[^a-zA-Z0-9_\x7f-\xff]/', '', $tag['NP']['design']);
+
+		return $safe_design . '_' . abs(crc32($tag['file'])) . '_' . $tag['line']; // Former name '__lambda'.
+	}
+
 }
 
 class _Tag_RenderElements extends _BlockTag {