by Mary Cooch.
Ok first of all, coming to this from several months later (sorry Tom) teachers can't log in as students unless the admin expressly allows them that capabilty -which is up to your admin. The 20 files max upload refers to the number of files each individual student can upload to one assignment (dropbox?) and not to the number of files a teacher uploading for a student could upload. There was in 1.9 a place in the code where you could increase this number (I remember finding it and posting it ) but I don't think you necessarily need that Tom. Dot - if you need it I will try to find it again)