ZacMatic: I have the same problem. I'm on Windows 7 64-bit and I downloaded the new release of Myst: Masterpiece Edition from GOG. Everything works fine--the Quicktime videos, the interface, saving and loading.
However, at seemingly random times, the game freezes. If any sound is playing at the time, it will loop. The only thing I can do at this point is bring up Task Manager and kill the process.
For what it's worth, I actually had no problems with the Quicktime videos in the previous version, as long as I ran the game in Windows XP compatibility mode, but I had the exact same random freezing issue.
Does anyone have any ideas?
I'm on Windows 7 x64 and I've found that running it on XP compatibility mode makes it much more likely to crash. Since GOG updated the game for W7 compatibility, the only crashes I've had have been when running it in compatibility mode (I was trying to see if it helped with a different bug I'm having, the mechanical age fortress controls don't work properly).