Sounds strange. What exactly does happen to the data? Can your script print it out or save it to a temp file to verify that it's in the correct format? My hunch is that the uploaded file isn't any different from the files you've been testing with in the non-CGI environment, with the possible exception of end-of-line characters. However, I don't think you'll be able to get much more than stabs in the dark from the monks here unless you can post the relevant file-parsing code from your CGI script.