Multiple CG installations on multiple subdomains

[eluser]thisischris[/eluser]
I've set up a subdomain http://devtest.localhost
Which points to 'C:/xampp/htdocs/sub_domains/devtest'

I've also modified the config file to include 'http:/devtest.localhost/' as the base_url.

All seems to be working fine except I'm guessing the routing being done.

Code:

<?php echo form_open_multipart('upload/do_upload');?>

It generates the correct action url : "http:/devtest.localhost/index.php/upload/do_upload".
However when I click on submit I get redirected to: http://devtest.localhost/devtest.localho.../do_upload

In htdocs/ I have the following .htaccess file:

Code:

RewriteEngine on
RewriteCond $1 !^(index\.php|user_guide|sub_domains|resources|robots\.txt)
RewriteRule ^(.*)$ /index.php/$1 [L]

Any ideas?