Automatic published posts are not seen

Hi (and in advance, sorry for my english):

I was building a site for a group, with some tools. One of them is to make the publication of the blog automatic, while they write in their particular blog, through a RSS.

I used, with success, the WP-o-Matic. And it work very well. Don’t know how, but suddenly the posts already written by this tool, which before were visible and sorted by categories. I use twentytwuelve theme, and the categories in which the posts were placed are still showed in the categories widget. I can also go to the post through the direct link, and it’s still there.
Some examples:
– Blog, with manually written posts.
– If you try the category “Acollida” clicking in it (is active because it has posts inside), is empty. Here you can see a post categorized there.
– And pay attention to the difference! In the widget “Recent posts”, in a category page or the main blog page you can’t see this missing posts, but from a post page is possible to see all of them!

I tried to copy the older posts and publish them manually, and all goes as normal. Then another automatic feed was published by the WP-O-Matic (correctly published, also by a admin autor), of a new category, and the new category is displayed in the widget of categories, but the post is imposible to see.

However, when I edit a automatic published post I can’t see, sometimes (not always) I can read: “There’s a more recent automatic copy of this posts. See it” (fast translation of the system message), with this link: http://mancomunidadeintegralgalega.net/wp-admin/revision.php?revision=193&action=edit, I click in “Restore”, and the post is well published. But only whit some posts!!!

The last things I did were write some JavaScript code in the page.php template (but two functions with no relation at all, and I tested anyway restoring to the old version); added some “a” tags to the categories description (where the overlimited html is automatic erased); and I was trying some calendars plug-ins. I have now the amr-ical-events-list. I tested after unactivating this plug-in, but still the same.

I didn’t make changes to index.php, archive.php or recently to category.php. I think the problem should be over there, maybe between the loop and somewhere else. But don’t know what could be done to stop the good working of the site.
I remember that a plug-in called “all-in-one-event-calendar” instaled some themes when I made the upgrade. It gave problems with the installation of the upgrade, and was no posible to use the admin panel, so I removed it directly from FTP. Now remains a empty folders, that the FileZilla want not to remove, inside this plug-in folder. This is the path: app/view/admin/js_src.

All help will be well received. Thanks in advance for your time. And if you need some more info, ask for it.