I'm struggling about the freezing issue on my Windows 7 64 Bit more and more now. As another user already wrote here, unchecking the multithreading option is useless on this platform, and I don't really want to get the results slower than (theoretically) possible, too.
Slicing the image library isn't also a valuable option, if you've big folders.
So, please, the last update's been published a long time ago already. I'd also be ready to pay for an upgrade to 4.x, if this multithreading feature would work without problems then. And, for sure, the other known problems mentioned here should be fixed than, too! ;-)