Some ISPs will cause a chmod problem when you try to create a new file or html page using a Perl script.
For example a postcard script will usually create a new page for every new postcard. If the ISP causes a chmod of 711
for security reasons, then no one except the site owner will be able to see the postcards.
Or call this script at the end of your script;
In your script put,
at the bottom of your script and upload chmod.cgi as below to the same directory. (Rember to alter the Shebang line and change chmod command 777 to desired value if necessary).