How are you triggering notes? And what are you expecting?
It works for me using this PHP class.
Example:
require 'OSC.php';
$c = new OSCClient();
$c->set_destination("127.0.0.1", 8000);
$m = new OSCMessage("/renoise/trigger/note_on", array(
-1, 0, 100, 60
));
$c->send($m);
$m = new OSCMessage("/renoise/trigger/note_on", array(
-1, 1, 101, 80
));
$c->send($m);
$m = new OSCMessage("/renoise/trigger/note_on", array(
-1, 2, 102, -10
));
$c->send($m);
$m = new OSCMessage("/renoise/trigger/note_on", array(
-1, 3, 103, 200
));
$c->send($m);
$m = new OSCMessage("/renoise/trigger/note_on", array(
-1, 4, 104, 128
));
$c->send($m);
Invalid data rejected, the rest is fine?