Symbols seem to do strange things as well. The input was :

  !@#$%^&*()_+ 

here's 3 runs of it with bias all the way down:

http://paste.click/KNIJov

http://paste.click/PPjKXC

http://paste.click/RtZCtG

As I turned up the bias, it seems to trend to the letter g:

http://paste.click/hJrVlX

Some symbols seem to just fail, I'm guessing that's a bug in the serializing.