I am using the 2.0.5.2 XOOPS version and I realized that I can't obtain any result when searching for user_url, user_from, user_intrst or user_occ criterias (others fields are working properly) in the system\admin\findusers\main.php page. Is it a bug

I confirm that I'm not the only one to have got the same problem...
I have upgraded to the 2.0.6 version and it doesn't change anything. I confirm that I'm talking about the findusers function in the admin system module. Is there anybody that found the solution? (I suppose in the findusers\main.php page)

I corrected the file, you can find it to
http://membres.lycos.fr/winsion/modules/mydownloads/

Apparently your modif is only concerning the user_url field (line 206 of findusers/main.php) but doesn't solve the pb

In fact the solution is to modify the lines concerned in the findusers/main.php page according to the following presentation:
case XOOPS_MATCH_START:
$criteria->add(new Criteria('user_fieldx', $myts->addSlashes(trim($HTTP_POST_VARS['user_fieldx'])).'%', 'LIKE'));
break;
case XOOPS_MATCH_END:
$criteria->add(new Criteria('user_fieldx', '%'.$myts->addSlashes(trim($HTTP_POST_VARS['user_fieldx'])), 'LIKE'));
break;
case XOOPS_MATCH_EQUAL:
$criteria->add(new Criteria('user_fieldx', $myts->addSlashes(trim($HTTP_POST_VARS['user_fieldx']))));
break;
case XOOPS_MATCH_CONTAIN:
$criteria->add(new Criteria('user_fieldx', '%'.$myts->addSlashes(trim($HTTP_POST_VARS['user_fieldx'])).'%', 'LIKE'));
break;
(which was not previously the case)