3 days for installationMc control don t work with N 5.1. Why

Hi

Mac OS 10.6.7/Nuendo 5.1.1.651.

My mc control don t work with Nuendo. I download EuControl v2.5.7 (I tryed also with v2.5.6). I search in u r forum. I make all recommandations:
http://nuendo.com/phpbb2/viewtopic.php?t=22394&postdays=0&postorder=asc&start=25&sid=23920fe2e6f7334418c8a68894dea815
http://www.steinberg.net/forum/viewtopic.php?p=30632

So the connection work with Mc Control and my computer. When I open Nuendo the Mc control “see nuendo” for few secondes and after lost the connection (no Nuendo parametres in the screen s mc control) . If I click in the finder and after in the nuendo, I find the connection with nuendo for few seconde. So any ideas?
I have N4 and N5 in my computer maybe it s a problème?

Thank

Laurent

maybe a bad cable?

Thank you for the answer but I try too other cable. No way.