It basicly states that the "=" sign in a URI is reserved as a delimiter sign. Therefore I recommend you not to use it as a non-delimiting sign within your URI (especially because the HTTP scheme is using it as delimiter for parameter keys and its values)
Thanks for your suggestions, but it doesn´t work for me. I must be doing something really wrong, because it seems to append the last url whenever I request a new page on my list.
Thanks to your post I have found this other link. At the end, somebody said his problem was with the .htaccess file.
I checked mine and I changed this line:
RewriteRule ^(.+)$ index.php?$1 [PT,L,QSA]
for this other one:
RewriteRule . index.php
And my pagination started to work . Thanks for your help to everyone.
Howewer, I don´t understand the difference between the two lines changed. Will I have any other problem with this new line in my .htaccess? I´m not pretty good with .htaccess rewrite sintax.