检察注册表的下面这些键值，有可能存在过长的键值导致，曾在2009-03-4遇到过此问题，用此法解决了。
HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \
Internet Settings \ 5.0 \ User Agent
HKEY_CURRENT_USER \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Internet Settings \ 5.0 \ User Agent
HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Internet Settings \ User Agent
HKEY_CURRENT_USER \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Internet Settings \ User Agent
