"i have record multicast over dumprtp localy (on the Wowza) multicast not freezing, no cubes in the picture"
"i conected wowza directly to network card of another server, the same problem"
Can you explain a little more? What is different about the second scenario? Are you recording in the second case? Can you go back to the first working case? Maybe if you specify the exact steps to replicate the problem it will help.