Steps to reproduce: have a dot in the metadata @match block.

eg,

// ==UserScript==
// @name         match block test
// @match        *://*.4chan.org/*
// ==/UserScript==

console.log('hi');

And then go to a site with a similar name that shouldn't be matched, like http://1d4chan.org/

Expected Result: Nothing should be echoed on the clipboard.

Actual Result: 'hi' is echoed on the clipboard.

I also note that the documentation of match patterns state that this should not be the case:
https://developer.chrome.com/extensions/match_patterns
http://wiki.greasespot.net/Metadata_Block#.40match