Thank you for you kind update
My website is: http://tinyurl.com/3uyuanz
I just added more command on robots.txt :
Not sure if this correct ?
Also not sure if the current W3 Total Cache Plug-in is concern with the URL 404 error ?
After that try delete plug-in that seem to related to link generation issue like sitemap, link checking, bot checker plug-in.
I also deleted the file sitemap in the server as i'm not sure if this file link to invalid URLs ( as this file might generated from plugin that not compatible with my permalink/ word press config.)
Will see one or two days for update about crawling issue.
Thanks Mr. Juggledad and all Readers.