I'm trying to use mediafire's new REST API, but I can't get the signature for the session_key right.

Here's their wiki: http://developers.mediafire.com/index.php/REST_API

According to them, this format should work:
Code:
email + password + application_id + API Key
But it doesn't. So I tried removing the spaces between the pluses, didn't work. Also tried removing the pluses too, didn't work. Anyone that's familiar with hashing stuff like this that maybe know what they mean?

EDIT: yeah I also asked their support about it, the first answer I got was to check their wiki (even though I wrote that the format on their wiki didn't work). The second answer I got was the format, copied from the wiki, with no example nor any clarification. Now I am waiting for the third answer....