[Gorka Urrutia]

Ok, solved.

I edited the .po file and changed:

msgid “post”

msgstr “mensaje”

to:

msgid “post”

msgid_plural “posts”

msgstr[0] “mensaje”

msgstr[1] “mensajes”

I also had to set plural forms (in catalog options) to:

nplurals=2; plural=(n != 1);

I’ve found the hint to the solution here:

http://drupal.org/node/17564