This is a question where ambiguity reigns. According to spec, it will only block it, if the url STARTS with that match:
This can be a full path, or a partial path; any URL that starts with this value will not be retrieved. For example, Disallow: /help disallows both /help.html and /help/index.html, whereas Disallow: /help/ would disallow /help/index.html but allow /help.html
useragent * Disallow: /this.htm
That would only get: /this.htm
But would also get: /this.htm/rocks
The problem is, that I don't believe all spiders follow the spec that way. They tend to do sliding regexs.