I have not been able to upload documents (pdf, in this case) larger than about 13.5 MB, either with the drag & drop Firefox plugin, or by using the content upload mechanism when creating a new document via the web interface. In each case, it quietly fails after a long wait. It seems as if it must be a time-out setting somewhere, but I don't know where. I haven't been able to pinpoint the critical point in the server logs. What controls the maximum file size? I need to be able to upload pdf files in the 30 MB range. By the way, I'm running version 5.4.2.