Added NULL checks for the CConfigParser::ReadString()'s parameters (http://code.google.com/p/rainmeter/issues/detail?id=105).

The font and registry handle are now free'ed properly if Initialize() is called multiple times.

Library/MeasureRegistry.cpp

@@ -154,6 +154,7 @@ void CMeasureRegistry::ReadConfig(CConfigParser& parser, const WCHAR* section)
 	}
 
 	// Try to open the key
+	if(m_RegKey) RegCloseKey(m_RegKey);
     RegOpenKeyEx(m_HKey, m_RegKeyName.c_str(), 0, KEY_READ, &m_RegKey); 
 }