Er, it's 'upload', not 'update'. Imagefield also does it the right way.
-rw-r--r-- 275 README.txt
-rw-r--r-- 434 filefield.css
-rw-r--r-- 103 filefield.info
-rw-r--r-- 673 filefield.install
-rw-r--r-- 24286 filefield.module