I used http://www.nexusmods.com/skyrim/mods/5755/? - pre-release - update 4 to optimize and http://www.nexusmods.com/skyrim/mods/247/? 2.0 to repack .BSA files. Now programs like ASIS claim Unofficial Dawnguard Patch missing masters like Dawnguard.esm. Wrye bash and MO do not show plugins with missing masters. I have read repacking vanilla BSA can be problematic.