Thanks for the help, I think we could be on to something here.
Regardless of whether or not FulltextSearchable is enabled, Firebug gives me a missing js file error when I hit the Edit button on a Wiki page:
"NetworkError: 404 Not Found - http://localhost:8888/tdg_SilverStripe-v2.4.7/sapphire/thirdparty/tinymce/plugins/sslinks/editor_plugin_src.js?m=1328047223"
The only reference to editor_plugin_source.js in the simplewiki code is in the Edit function in WikiPage.php line 402 as follows:
public function edit()
That js file starts with the following code:
// Load plugin specific language pack
Perhaps there's some issue with creating that plugin? There's certainly no reference to sapphire/thirdparty/tinymce/plugins/sslinks/editor_plugin_src.js in the wikipage code at all so I'm guessing it must be something it's trying to create on the fly.
Firebug pops up one other error:
$ is not a function
var element = $(element);
Not sure if that has any relevance.