I have a form on my site that allows users to upload files to a specified folder. Everything works fine in development, but on the production site im having some trouble with pdf files. Some files are working and others are showing as 0kb in the uploaded files folder, i am also receiving errors such as "File does not begin with '%PDF-. i have checked a lot of thing including the framework versions, ive ensured that there is no difference in the code and have even checked the AspMaxRequestEntityAllowed value in iis 6.0(thinking it may be a size issue). any ideas???