gtk-perl help

[Steve Cresawn <scresawn ufl edu>]

I'm writing an application using the GTK-Perl bindings, and I have a
fairly simple question.  Within a subroutine of my application, I need
to start another external application.  This will be done repeatedly, as
calls to this external application are numerous.  This application takes
a while to run, say 10 seconds or so, and during that time, the GTK
windows do not redraw.  I have been experimenting with many ways to
start this process (fork, system, open), and also using the waitpid
function.  It is important that after a process has been spawned it is
allowed to complete before it is called again.  I have also tried
including statements such as the following:

while (Gtk->events_pending)
    {
    Gtk->main_iteration;
    }

Still no luck.  I'd really appreciate some help with this.
Thanks,
Steve