Got a message from tech support of DreamHost about broken links within my blog. They said "because I set up permalinks, which writes a .htaccess file to my home directory. I also setup linking protection, which overwrote that. There's no way to have BOTH of those set up, unfortunately...."
I am confused. Linking protection is to stop sites outside to link images or large size content in my site to save bandwidth. But my internal links are all broken which must be something to do with databases!
They said they have fixed it for me which I can't see at the moment. It's either the instruction of WP is wrong or they are wrong.