I've discovered that strings with whitespace are
not read correctly with JSON.st. The parser calls
the next method which gets the next token and not
the next character from the stream.

Here is a patch that will parse from the stream
directly than from self in nextJSONNumber and nextJSONString:

http://www.ta-sa.org/files/txt/ce61efc9a954ece8f4d5ff1256e38a1c.txt