You definitely cannot install DFM 1.1 onto LMS 2.6. The requirement for LMS 2.6 is LMS 2.5.1 which included DFM 2.0.3. If you do not have the CDs for LMS 2.5.1, then you shouldd have them for LMS 2.5 which includes DFM 2.0. If you do not have any of your LMS 2.5 CDs, first check http://www.cisco.com/upgrade/ to see if you are entitled to get a spare set. If you do not see LMS 2.5 there, then you can contact the TAC for a replacement RMA.