Stub is correct, those domains are expired and they were auto renewed for free by the registry Verisign for 45 days. The registrar MelbourneIT has 45 days to pay and renew those domains. If they are not renewed the auto renew will be reversed and expiration day will show again the old date 2010-09-05.
MelbourneIT will allow the original owner around 20 to 25 days after expiry to reactive his domain. After that they will send it to auction at their partner auction house. This is not fair but this is how the domain industry works. This first auction is called pre-release auction and it happens within those 45 days while the registrar, in this case MelbourneIT, has still control over the domain.
If the domain is not sold during pre release auction it will drop after another 45 days after the auto renew. So this is around 90 days from expiry. When it drops it can be caught by a dropcatcher site like snapnames or namejet and then it will be auctioned again if there are more bidders. This is called a pending delete auction. Too many less experienced domainers are focused on pending delete domains which I don't suggest.
Basically even though these domains are expired the whois info doesn't show them as expired. This is the reason why some monitoring services don't work correctly because they monitor whois changes which can not be trusted.
In fact the domain agrotiendacampesina.com is right now on auction and you can see it on my website. Just go to the home page of my site and paste the domain into the first search box and it will show you a link to the correct auction house. It will also show how much time is left for you to join.
By the way, talking about those other monitoring services that don't work, there is one monitoring service that does work. In the future if there are other domains like this you want to track, just add them to domain monitor on my site and you will receive an email with all the details.
I wrote slightly more than you asked because you are a new member and I thought you might be new to domaining. I hope this helps.
Erdinc