User 1 becomes anonymous on node/add, access denied messages
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  Solved it!! It had to do with the .htaccess file! I needed to comment
  the following with regard to SSL Certificates.

# SSL Certificates
#  RewriteCond %{HTTPS} !=on
#  RewriteRule (user|admin) https://%{SERVER_NAME}%{REQUEST_URI} [L,R]
#  RewriteCond %{HTTPS} !=off
#  RewriteRule (node/*/edit|node/add/*) http://%{SERVER_NAME}%{REQUEST_URI} [L,R]

  
  I am not entirely clear on why it suddenly worked, but obviously it
  has something to do with these rewrite rules.