I was having the same problem with 7077
I just upped from 7048 to 7077. For whatever reason, the one of two drives in my rig wasn't reading the disc. Well actually, it was but just really slow. I tried installing it from my other drive which isn't quite as fast and the install was fine... no issues at all. Since moving to 7077, I've been having an issue trying to get RAID setup again, I didn't have any problems with the last build but this one keeps locking up on me...... Hopefully since RC's out next week it's all good.
]