How to get rid of the delay after the real work is done?

I am totally new to POE, so this might be a silly question but I looked
at the mailing list archive and the FAQ and didn't find the answer.

What I want to do is a parallel web client. For this I found a good
recipe in the POE cookbook http://poe.perl.org/?POE_Cookbook/Web_Client
The first example looked exactly like what I was looking for so I copied
the code and only added a few more URLs to @url_list.
Everything went fine, I got the web pages very fast but then after the
real work was done (all pages displayed) I had to wait for another 5
seconds until the script ended.
When I did this with the real pages I want to get (some JSON results)
and a bit of Time::HiRes output the relation was 4 seconds for the
actual work and then the 5 seconds delay until I could proceed.
If I could speed this up to the 4 seconds needed for the actual work,
everything would be fine and so much better than 9 seconds. How can I
achieve this?

Eventually I want to wrap this script into a method of my application,
call it with a list of URLs and return the combined result. The
application is a mod_perl web app. Are there any issues with this setup
I should watch out for?

Thanks
-Michael