Stopping cgi after user stops browsing

I have some Perl/Apache/rewrite rules that allows user to download data eg www.ipo-australia.com/download/200301.zip?format=fcharts
These downloads range from 100KB to serveral MB.

When a user hits 'stop', the cgi still keeps runing, eventhough I can see no data is being sent thru the ethernet port.

I have tried to trap sigpipe using the following Perl code but the cgi still runs.

eval {
local $SIG{PIPE} = sub { die "die\n" }; # NB: \n required

};

I have seen this question asked before but can't find a solution that works.

gtoomey