First, you may wish to read my CGI course to get an idea of better methods of handling CGI data. For your program, you can alsor read How to get your CGI scripts working (written by our own tachyon).

Have you tried running the script from the command line? If so, what does it say? Have you checked your error log?

You may wish to try the following:

#!/usr/bin/perl -wT
use strict;
use CGI;

my $poll_results = 'poll_results.txt';

my $cgi = CGI->new;
open POLL_RESULTS, ">> $poll_results" 
    or die "Cannot open ($poll_results) for appending: $!";
$cgi->save(POLL_RESULTS);
close POLL_RESULTS                    
    or die "Cannot close ($poll_results): $!";
[download]

Cheers,
Ovid

Update: D'oh!!! As chromatic just pointed out to me, you state that you have read the error log. I wasn't paying attention. I wonder if people upvoted me for that suggestion (and also weren't paying attention) or for my code snippet :)

New address of my CGI Course.
Silence is Evil (feel free to copy and distribute widely - note copyright text)