When migrating from Blogger to WordPress, I ran into to little problem where a URL (with http://) would not work no matter what. If you try it 403 forbidden error would pop up (even with the urlencode). It would work if you remove “http://”. This is actually the core mod_security rules.
“HTTP protection – detecting violations of the HTTP protocol and a locally defined usage policy.”
All you have to do is, ask the customer support representative to disable / Whitelist this rule. Hostgator support were happy to do this.
If you know how to do it manually (dedicated server) and want to share your experience, please comment. Would appreciate that. 🙂