MATLAB 2013b freezes on Mavericks?

I installed MATLAB R2013b on my Mac Mini (2.5GHz i5, 4GB RAM, running Mavericks), which is supposed to be sufficient for running MATLAB? But it freezes quite often, about every hour. Before I got the Mac, I had 2012b installed on my 4-year-old windows 8 laptop (but with 6GB RAM), and it worked perfectly fine.

On the Mac, it not only freezes, but is also significantly slower. It takes like a minute to boot up Simulink.

What could be the reason? And how would I resolve it? Thanks.