Symantec Endpoint Protection RU6 MP1 (11.0.6100) provides fixes since the release of RU6 and RU6a. This maintenance patch cannot be installed over any versions of Symantec Endpoint Protection or Symantec Endpoint Protection Manager prior to RU6. It must be installed over RU6 or RU6a.
You should be able to download the RU6a build from Fileconnect.
http://www.symantec.com/business/support/index?page=content&id=TECH103087&locale=en_US
Moving this thread to the Endpoint forum.
Thomas