Oh, ok. Well I’m surprised my demo doesn’t work for you. It works perfectly for me.
What browser / OS are you using?
I changed my cookies from “when close” to “when expire”
I got only one pop-up here http://hibbard.eu/display-ui-blocking-overlay-on-page-load/
But http://hibbard.eu/blog/pages/disclaimer/ is the same every time
Edit
I just tried the second link again and no “agree” this time.
Maybe a cache thing?
1 system with win7 and firefox 29, IE8, chrome (version can’t remember now, but i suppose latest)
1 system with win7 and firefox portable 28, IE9 (and firefox 29)
1 system with winXP and firefox 28, IE10 and chrome (version unknown, but i suppose latest)
also, i think i identified my problem: most of the time i use the second system with firefox portable 
and as i see it now, this is not saving/keeping any tempfiles … it’s probably the reason why the pop-up always return to me.
opening it with and installed version, i get the pop-up only once, so, BIG Apologize accusing your script to not working.
deleting cookies, not suppose to return the pop-up? asking this because it i’m not getting the pop-up again after cookie deletion, even on browser restart … :(
(i’m stressing you? )
my mistake again :D, apologize
So it’s working now?
It works for me with Firefox 29 the last few times I tried.
yes, it’s working, thank you.
but i have another question:
if i already use (load) <script src=‘http://code.jquery.com/jquery-latest.js’ type=‘text/javascript’/>
i need to load this one too? <script src=“http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js”></script>
<Homer Simpson voice>WooHoo!</Homer Simpson voice>
No. You only need to load jQuery once per page, otherwise the second version will overwrite the first and you’ll get things breaking unexpectedly.
<Homer Simpson voice>WooHoo!</Homer Simpson voice>
two more things (before anothers)
i suppose i will keep the <script src=‘http://code.jquery.com/jquery-latest.js’ type=‘text/javascript’/> one, yes?
and i can combine by simply append (copy.paste) jquery-latest.js and jquery.cookie.js to have only one external script loaded?
I prefer Google’s CDN, as it is used by more people.
This means that there is more chance of a user having the Google CDN version of jQuery cached from another site.
But saying this, there isn’t a big difference which you choose.
As jQuery is being included via a CDN, then copy/pasting won’t work (although the idea is correct).
Great stuff and an interesting page, too (I had a look at it using Google translate).
Thanks for taking the time to report back.