Ditto on Abigail-II's suggestion. Not looking at the error logs is like trying to divine the cause of an engine problem by looking at the outside of the car.

Show some due diligence and you're apt to find you get much more help around here.
Having said that, for testing, you can use CGI::Carp to see the errors in your browser.

use CGI::Carp qw(fatalsToBrowser warningsToBrowser);
[download]

Usually these types of problems are caused by something being printed (an error or warning) before the header is sent to the browser.

-Lee

"To be civilized is to deny one's nature."