I figured out the problem here. XP was popping up File security warning everytime I opened the chm file. Even though I was clicking ok the chm would come up with no content. I unchecked the box that said "Always ask before opening this file" and now everything works fine.
Hopefully that will help somebody some day.
说来奇怪,将XP的那个警告的勾勾去掉就可以了,在此仅作为问题的一个记录
原文档请到这里看：
http://www.hibernate.org/hib_docs/nhibernate/1.2/reference/en/html/index.html