I have disabled the use of the Media Library Manager when uploading images on the frontend by unchecking the "Use the WordPress Media Library manager for image, video, audio, or file fields " box on the relevant forms. Up to Forms 2.6.9, an image upload field showed a "browse" button inside a form field and this worked just fine. Having updated to 2.6.10, this has been replaced with an "Upload or Select" button which takes the user to the Media Library to upload their images. This shouldn't happen since I've disabled this on my forms.
I've tried enabling the Media Library Manager, saving the form then disabling it again but this hasn't had any effect.