ok alors si je comprends bien
uid c le uid de l'utilisateur
friendid c sense etre uid d'un ami
blockeduid c sense etre l'uid que tu as bloques
En gros tu veux savoir si l'uid que tu veux rajouter est dans ta liste d'utilisateur bloque ou ami
Ton avant dernier essai est presque bon :
case "addfriend": // Add someone to your friendlist
$member_handler =& xoops_gethandler('member');
$thisUser =& $member_handler->getUser($friendid);
if (!is_object($thisUser) || !$thisUser->isActive()) { // Only add valid profiles as your friendlist
redirect_header("myfriend.php",3,_PROFILE_MA_SELECTNG);
exit();
}
$sql = "SELECT Count(*) FROM ".$xoopsDB->prefix("mylove")." WHERE (uid=$uid AND blockeduid=$friendid)";
$res = $xoopsDB->query($sql);
list($ismyfriend) = $xoopsDB->fetchRow($res);
if ($ismyfriend == 0) {redirect_header('myfriend.php',5,_MLS_BLOCKED_PROFIL);
exit();
}
$sql = "SELECT Count(*) FROM ".$xoopsDB->prefix("mylove")." WHERE (uid=$uid AND fuid=$friendid)";
$res = $xoopsDB->query($sql);
list($ismyfriend) = $xoopsDB->fetchRow($res);
if ($ismyfriend == 0) { // This member isn't your friend yet.
$sqlstr ="INSERT INTO ".$xoopsDB->prefix("my love")." (uid, fuid) VALUES ($uid, $friendid)";
$req1=mysql_query($sqlstr);
redirect_header('myfriend.php',5,_MLS_FRIEND_ADDED);
exit();
} else {
redirect_header('myfriend.php',5,_MLS_FRIEND_ALREADY);
exit();
}
ton erreur est sur ton test de redirection pour tester si c bloque
tu dois pas tester si c == 0 mais au contraire si c'est different, et oui si tu recuperes rien c justement que ton utilisateur n'est pas bloqué

Donc a priori avec la comprehension que j'ai de ton pb ca serait plutot cela
case "addfriend": // Add someone to your friendlist
$member_handler =& xoops_gethandler('member');
$thisUser =& $member_handler->getUser($friendid);
if (!is_object($thisUser) || !$thisUser->isActive()) { // Only add valid profiles as your friendlist
redirect_header("myfriend.php",3,_PROFILE_MA_SELECTNG);
exit();
}
$sql = "SELECT Count(*) FROM ".$xoopsDB->prefix("mylove")." WHERE (uid=$uid AND blockeduid=$friendid)";
$res = $xoopsDB->query($sql);
list($ismyfriend) = $xoopsDB->fetchRow($res);
if ($ismyfriend != 0) {redirect_header('myfriend.php',5,_MLS_BLOCKED_PROFIL);
exit();
}
$sql = "SELECT Count(*) FROM ".$xoopsDB->prefix("mylove")." WHERE (uid=$uid AND fuid=$friendid)";
$res = $xoopsDB->query($sql);
list($ismyfriend) = $xoopsDB->fetchRow($res);
if ($ismyfriend == 0) { // This member isn't your friend yet.
$sqlstr ="INSERT INTO ".$xoopsDB->prefix("my love")." (uid, fuid) VALUES ($uid, $friendid)";
$req1=mysql_query($sqlstr);
redirect_header('myfriend.php',5,_MLS_FRIEND_ADDED);
exit();
} else {
redirect_header('myfriend.php',5,_MLS_FRIEND_ALREADY);
exit();
}