Hey, just FYI for your tutorial, you can remove the symlinking instructions for aircrack-ng.

As I'm the current maintainer of the aircrack-ng package, I have implemented both optification of the binaries (so they no longer get installed to /usr/local/[s]bin/ anyway), and symlinking them into the default path (to /usr/[s]bin/) now happens automatically too.

You could, you know, post in the Aircrack-NG 1.1 thread that you're experiencing this bug. Also, if you're using it with faircrack or some other scripts, instead of directly, it's possible the freezes are because of the above mentioned installation path changes.