The links you use are old. That is because the Fajr-3 artillery rocket is an old system. However, Fajr-3 MIRV is from 2006. FAS, Globalsecurity, are sites that barely get updated with very old information. See news links: 
 *Iran Says New Missile Test Successful 
 *Iran tests second new torpedo in Persian Gulf 
 *Iran claims a successful test: A missile that can avoid radar