This works for me:
db.define_table('image',
Field('name'),
Field('file', 'upload'))
def index():
image = db(db.image.id==request.args(0)).select().first()
form = SQLFORM(db.image, image, upload=URL('download'))
if form.process().accepted:
response.flash = 'image saved'
return dict(image=image, form=form)
