has_one file relation not working on front end forms

[codivist]

when using uploadify on a front end form, the has_one (e.g. 'Resume' => 'File') is not submitted with the form in the $data array, but the FolderID where the file is going is.

Using your example form http://www.leftandmain.com/silverstripe-tutorials/2010/08/30/using-uploadify-in-frontend-forms/ in SS 2.4.5 and the latest version of Uploadify from here, the $data array comes back as:
Debug (JobApplicationPage_Controller->sendForm() in line 198 of JobApplicationPage.php)
url = /about/jobapplicationpage/ApplyForm
FirstName = Test
LastName = test
Email = test@example.com
Position = Sales
FolderID = 189
SecurityID = 08525d6c8a71b25c02
Captcha = 7

The file is uploading and Charles returns http://newTest.localhost/about/jobapplicationpage/ApplyForm/field/Resume/refresh?FileIDs=219

The file upload is working, and javascript is returning the ID of the uploaded file, but its not being submitted to the form data on submit.

[codivist]

I guess I should mention that because of the above, it makes it so the uploaded file can NOT be attached to emails.

[codivist]

upon further investigation I have found that the uploadify form doesn't work when the form is submitted via ajax, and your site MUST be in LIVE mode.