Answer:
NetView currently only supports like-like configurations (meaning AIX-AIX
,Solaris-Solaris, etc). We're working on a fix now that will allow any
Netview UNIX client to work with any NetView UNIX server.
              ******************************************

With V5.1 you are now allowed to combine AIX and Solaris clients and
servers.

Digital Unix is still restricted to Digital Unix client and server.
NT is still restricted to NT client and server.

Tivoli Verification - RTP