Felipe,
You're English is perfect. I wish everyone posted as clearly as you
As for the Like button, when I click it, it flicks back to 0 immediately so that the count doesn't 'stick'. Not sure how much you know about your server config, but there is one odd thing I'm seeing. If I run your page through the Facebook URL Debug Tool, it reports that your page is responding with a 206 status code. Normally, it should respond with 200, which means "OK". 206 is an indication of heavy caching where only a part of the page is sent:
developers.facebook.com/tools/debug/og/o...ww.mundodeportivo.cl
Facebook won't request the whole page in this case. When that happens, they don't get to scan the whole page for the proper tags or even structure of your page. The result is that your page, to Facebook, looks like the following HTML:
developers.facebook.com/tools/debug/og/e...mundodeportivo.cl%2F
If you scroll to the very bottom, you'll see that the content of your page is abruptly stopped less than half way through. It's possible that Facebook is thinking your page is so badly coded that it simply won't let Like's go to that page. They don't want wall posts with really bad links (either bad/non-functional, malware, or spam pages).
So, if possible, determine what is causing the agressive caching on your server and try to disable it. It's possible it's a Joomla extension, but more likely an Apache configuration setting. I don't know how easy that will be to fix, and I can't guarantee that's the problem. We have seen multiple other issues related to 206 response codes on sites in the past though.
Hope that helps get you started and gives some background!
Alex