I have noticed a strange issue with MachForm. From the admin panel, if I create a new form with a file upload field, open that form and upload a file, the file is uploaded as I would expect. If I go back to the list of forms, open that form again and upload another file, the file is not uploaded properly and has a .tmp extension and a corresponding listfile. Looking at my various forms, they are all littered with these .tmp and listfile_ files to too.