http://topic.csdn.net/u/20071126/22/0c0941fd-fc09-49e1-ab61-16ad29237dc8.html
http://www.cnblogs.com/hsrzyn/articles/1674362.html
http://www.baidu.com/s?wd=DBNETLIN%20invalid%20instance&pn=0&tn=baiduhome_pg&usm=1