Please read my reply to you. In it, I mention that, when running under a webserver, the current directory likely is not what you think. Do not use relative filenames when running under a webserver.

You could have avoided a large part of this wild goose chase by making it clear from the start, in your top post, that you are running your script under a webserver account as a CGI script. That would've made it more clear to us where a likely cause for the error lies.