Flashdata being set but can't be echoed

[eluser]ChazUK[/eluser]
I have this in my htaccess file

Code:

RewriteEngine On
RewriteBase /

# this adds trailing slash
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !(.*)/$
RewriteRule ^(.*)$ $1/ [R=301,L]

# this gets rid of index.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1