After spending days, getting mad, asking and searching, why i couldn't see and connect my vepro5 to slaves, i found the answer...Unbelievable : It's the RealGuitar 2.3L !!!
In Logic 9, as a virtual instrument, when it's on, there is a conflict, which makes Vepro5 blind...It cannot see slaves on network. If you remove it, slaves appear ...
If it helps someone...Sorry for bad english, and Merry X-Mas to all.