I have this same problem, and I kind of know what the problem is, however, I still cannot access my D: drive. It is the hard drive where Windows 7 beta is installed. I can dual boot to Windows 7 beta still, and I told it to share my drive, but when I load up Windows 7 Ultimate, I try to double click on the hard drive, and it keeps saying Access Denied. I tried to go to the security tab and allow access, and it says it did it, but I still cannot access it! This happened before when I installed Windows 7 beta and still had XP on dual boot, but this time I can't access the hard drive!!