I use forking alot for intense SQL queries when the results of the queries doesnt matter to the user.

There are two ways to do the forking that Ive found that fixes your problem.

Method one: Fork with a location tag. Once the browsers receive the location tag they go away without waiting.

Example:

#!/usr/bin/perl
#
# do pre fork stuff here
#
if (fork) {
     #
     # Damn browser, go away!
     #
     print "Location: http://www.wherever.com/blah\n\n";
     exit;
}
#
# do post forking stuff here
#
[download]

Method two: Disable buffering and then close STDOUT.

Example:

#!/usr/bin/perl
#
#disable buffering
#
$| = 1;
#
# prefork stuff
#
if (fork) {
     #
     # stuff to display to user.  other processing that
     # the user needs to see, ect.
     #
     print "Content-type: text/html\n\n";
     print "Done";
}
#
# Close STDOUT;
#
close STDOUT;
#
# work in the background
#
[download]

Pete

insert into pete('red hair','green eyes','overinflated ego');