Just wantet to answer, but you were faster :-)
Some comments:
If you edit the meta tag, it should read <meta>_special_NAME, ...</meta> or <meta><![CDATA[_special_NAME, ...]]></meta>.
And you should remove your custom fields from the I18N Custom Fields plugin and add them to the special page type.
Some comments:
- what's really needed is the <special>NAME</special> (where NAME is the name of the special page type) - it is how the plugin recognizes, if it is a special page
- regarding the tags (meta): You don't have to add anything, if you can already identify your (now special) pages, e.g. you have a common tag for them. If you don't add the _special_NAME it it will be added the next time you save the page. It is only added for your convenience to have a unique tag for I18N Search.
If you edit the meta tag, it should read <meta>_special_NAME, ...</meta> or <meta><![CDATA[_special_NAME, ...]]></meta>.
And you should remove your custom fields from the I18N Custom Fields plugin and add them to the special page type.