At line 67 in timesheet.pl there was this:
print $q->redirect($uri, -cookie => $cookie);
Unfortunately it doesn't work with the -cookie, it just
causes a blank page. So I removed it and it works.
Maybe CGI.pm changed since 2003.
I'm using the CGI bundled in Perl 5.8.5 on Centos 4.3,
with Firefox 18.104.22.168, if it matters.