No Data Received

If your site is on GoDaddy, you need to talk to them – there are quite a few other threads on this topic today –

http://wordpress.org/support/topic/cant-save-posts-or-pages-in-361?replies=12

http://wordpress.org/support/topic/err_empty_response?replies=18

Update: The cause of this appears to be a new server rule being applied by GoDaddy. See http://wordpress.org/support/topic/godaddy-is-real-bad-company-and-there-blaming-wp-for-it

I suggest you contact GoDaddy and ask them about it.